UNITED STATES COURT OF APPEALS FOR THE TENTH CIRCUIT

________________ _________________ BEVERLY CRIBARI, Plaintiff - Appellant/Cross - Appellee,

v. ALLSTATE FIRE & CASUALTY INSURANCE COMPANY, Defendant - Appellee/Cross - Appellant. No. 19-1270 (D.C. No. 1:16- CV-02450-NRN) (D. Colo.)

________________ _________________ BEVERLY CRIBARI, Plaintiff - Appellee,

v. ALLSTATE FIRE AND CASUALTY INSURANCE COMPANY, Defendant - Appellant. No. 19-1343 (D.C. No. 1:16- CV-02450-NRN) (D. Colo.)

________________ _________________ BEVERLY CRIBARI, Plaintiff - Appellee,

v. ALLSTATE FIRE AND CASUALTY INSURANCE COMPANY, Defendant - Appellant. No. 19-1425 (D.C. No. 1:16- CV-02450-NRN) (D. Colo.) FILED United States Court of Appeals Tenth Circuit 

### June 3, 2021 Christopher M. Wolpert Clerk of Court2 ________________ _________________ ORDER AND JUDGMENT *

________________ _________________ Before MORITZ , BRISCOE , and CARSON , Circuit Judges.

________________ _________________ Plaintiff Beverly Cribari sued her underi nsured motorist in surance provider for breach of contract and bad faith. A jury f ound in Defendant Allstate Fire & Casualty Insurance Company’s favor on all counts. Plaintiff appealed th e district court’s denial of her summary judgme nt motion as well as various pretrial and trial rulings— Case No. 19-1270. Post-trial, Defendant sought to claw back a payment it made under a reservation of rights. After Plaint iff refused to return the check and filed a notice of appeal, Defendant filed a motion for leave to amend its pleadings. The district court denied that motion and De fendant appealed that ruling—Case No. 19-1343. Finally, the Clerk of Court for the United Stat es District Court for the District of Colorado entered a cost award for Defendant. After the Clerk declined to tax any expert costs beyond a forty dollar per day appear ance fee, Defendant sought review of the Clerk’s award, which the di strict court denied. Defendant filed a second appeal on this issue—Case No. 19-1425. Our jurisdiction arises under 28 U.S.C. § 129 1. We affirm the district court’s decisions in Case Nos. 19- 1270, 19-1343, and 19-1425.

* This order and judgment is not bi nding precedent, except under the doctrines of law of the case, res judica ta, and collateral estoppel. Itmay be cited, however, for its persuasive value consiste nt with Fed. R. App. P. 32.1 and 10th Cir. R. 32.1.3 I. An underinsured motorist ran a red li ght and struck Plaintiff’s vehicle. Plaintiff suffered a wrist in jury in the collision and se ttled with the underinsured motorist for his $100,000 policy limit. She later filed a claim with Defendant—her underinsured motorist (“UIM”) insura nce provider. Her UIM policy placed obligations on Plaintiff to a ssist in an investigation of the claim—specifically the policy required her to attend a medical examination, provide a medical authorization, and cooperate with Defenda nt’s investigation. Four months after Plaintiff’s filing of the UIM claim, Defendant asked Plaintiff’s counsel to return a signed medical authoriza tion and list of Plaintiff’s treating providers. After not hearing from Plaintiff’s counsel, De fendant offered to resolve the claim for $35,000, noting that it did not have evidence of future treatment expenses. Defendant asked about Plaintiff’s surgical options, costs, and how long Plaintiff would need to mi ss work. Plaintiff’s counsel responded that Plaintiff required surgery. The parties met in pers on and agreed that Plaintiff would see her surgeon to discuss her impairment rating, fu ture surgical options , a cost estimate for the potential future surgerie s, and any resulting compli cations. Defendant again asked for a medical authorization and a wa ge loss authorization. After a third request, Plaintiff’s counsel pr ovided the authorizations. Plaintiff’s counsel provide d Defendant with correspondence that purported to summarize Plaintiff’s surgeon’ s review of Plaintiff’s c ondition. Although it listed two surgical possibilities, th e correspondence lacked an im pairment rating, surgical4 cost estimate, or an estimate of how long Plaintiff would need to take off work. Defendant re-evaluated the claim and offere d to resolve it for $100,000. The offer accompanied a note that Defendant still di d not have the disa bility rating, cost estimates for future surgeries, or co rresponding wage loss . Despite the earlier meeting, Plaintiff’s counsel responded that she did not anticipate Defendant needing that information. She asked whether De fendant would pay for another appointment to obtain that information. Defendant ag reed. And Plaintiff’s counsel acknowledged she would schedule an examination “to obt ain the information Allstate needs to evaluate her claim, including the impairme nt rating, the physician charges for the future surgery, and the amount of time she is likely to miss from work.” Plaintiff retained a vocati onal rehabilitation forensic e xpert to develop a life care plan and analyze the cost and impact of Plaintiff’s future surgeries. She also retained a second expert to estimate her future medical expenses—a figure the expert calculated at $341,700. Plaintiff did not di sclose these experts until litigation. Plaintiff’s surgeon eventu ally sent Defendant a report that provided an impairment rating and suggested Plaintiff may require surg ery, but it did not provide a cost estimate for any surgery or describe the potential complications and time Plaintiff would need to recuperate. Th e surgeon later testified he could have provided a cost estimate, but that Plainti ff’s counsel did not re quest one. Defendant reassessed the claim withoutthe information it had requested and without knowing about the two expert reports. Defendant offered $115,000.5 Plaintiff did not respond to the offer. Rather, Plaintiff believed Defendant refused to make her a reasonable offer for underinsured mo torist benefits and sued Defendant in Colorado state court allegi ng, among other things, breach of contract and bad faith. Defendant removed the civil action to the United States District Court for the District of Colorado. In its An swer, Defendant asserted an affirmative defense to the breach of c ontract claim that Plaintif f failed to cooperate with Defendant’s investigation and comply with the policy’s terms. Defendant later explained in discovery that it raised a failure to cooperate affirmative defense because Plaintiff failed to pr ovide it with a cost estimate for a possible future surgery and associated wage loss. Defendant’s Rule 30(b)(6) corporate representative also testified that Defendant suffe red prejudice because it coul d not investigate the claim and incurred expenses to defe nd the claim in litigation. After a year of litigation, the parties me diated the case. Befo re that mediation, one of Defendant’s claims ad justers made an entry in De fendant’s claim log. That entry examined the claim, analyzed potential liability and Plaintiff’s potential damages, referenced the mediation, and noted the policy limits of $250,000. That adjuster noted a “gross tort value” up to policy limits. The day of the mediation, one of Defendant’s managers aut horized up to $250,000 to resolve the claim and noted that authorization in the claim log. The parties did not settle the litiga tion. But following the mediation, Defendant drafted a $250,000 checkto Plaintiff “on the possibi lity that it was owed.” The adjuster who authorized the check testified he had no intention of advancing the6 funds to Plaintiff. Defendant transmitted the check to its counsel, who determined that Defendant did not have to pay the funds because Defendant authorized the $250,000 to resolve all claims in the laws uit, Defendant was st ill investigating the UIM claim, and Defendant had asserted a coverage defense. As a result, Defendant’s counsel did not forward the check to Plaintiff. 1
Defendant made an offer of judgment for $200,000. Plaintiff rejected the offer. Defendant ultimately completed its investigation of Plai ntiff’s claim during litigation and determined that, but for her failu re to cooperate, Pl aintiff’s claim would be worth the full $250,000 policy limits. Defe ndant paid Plaintiff and her counsel $250,000, but reserved the ri ght to claw back the $250,00 0 should a jury determine that Plaintiff had failed to cooperate in Defendant’s claim investigation. The district court denied the parties’ cross motions for summary judgment on Defendant’s failure to c ooperate defense holding thata reasonable jury could conclude that Plaintiff cooperated in the investigation of the claim, but that a reasonable jury could also conclude th at Plaintiff did notcooperate in the investigation. The district court also determined that Defendant’s $250,000 payment did not render its defense moot and its abi lity to adjust the cl aim followed by its conditional payment did not preclude it fr om arguing prejudice from Plaintiff’s alleged failure to cooperate.

1 Before trial, Defendant ’s accounting department ma iled a letter to Plaintiff asking why she had not cashed the orig inal $250,000 check that she had never received—a routine function of Defendant’s accounting department if an insured has not cashed an issued check.7 In the proposed Pre-Trial Order, Defendant alleged th at Plaintiff, through her counsel, had intentionally “set up” Defendant for a bad faith case so she could obtain additional damages. Also befo re trial, both parties filed mo tions in limine. Plaintiff sought to preclude Defendant from presenti ng a “set-up” defense—in other words, Plaintiff desired to prohibit Defendant from arguing that her counsel knowingly and intentionally lied, concealed, and cheated Defendant for he r own financial gain. The district court denied that motion. Plaintif f also sought to limit Defendant’s failure to cooperate defense to issues contained in Defendant’s disc overy response. Plaintiff objected to this defense beca use she claimed that Defendant failed to plead it with particularity in its answer. The district c ourt also denied Plaintiff’s motion to limit Defendant’s failure to coopera te defense. Plai ntiff next sought to preclude Defendant from presenting a stealth fraud defense—m eaning that Defendantcould not argue that Plaintiff did not just merely fail to cooperate, but actively concealed information from Defendant. The district court denied in part and granted in part Plaintiff’s motion to preclude Defendant from presen ting a stealth fraud defense, stating, “[t]here will be no mention of fraud.” De fendant moved to allow the jury to know the measure of damages available in a bad faith claim in order to understand Plaintiff’s motive for allegedl y sabotaging Defendant ’s investigation of her claim. The district court allowed the jury to h ear that additional damages were available because of the bad faith clai m. Defendant additionally s ought to prevent Plaintiff from referencing mediation, issuance of a potential settlement check, and settlement negotiations. The district court excluded refe rence to mediation pr eparation, issuance8 of the $250,000 potential settlement check, and settlement negotia tions under Federal Rule of Evidence 408. At trial, the district court tasked the ju ry with deciding three claims: breach of insurance contract, unreasonable delay or denial of insura nce benefits, and bad faith breach of insurance contract . At the close of eviden ce, Plaintiff moved for a judgment as a matter of law on Defendant’s failure to coopera te defense and her breach of contract claim. The district c ourt denied that motion. A jury found for Defendant on all three claims. Although the jury heard evid ence on Plaintiff’s alleged failure to cooperat e, and although the district court permitted the jury to consider that evidence in deciding whether Pl aintiff should prevail, the district court, over Defendant’s objection, did not give the jury an inst ruction asking if Plaintiff failed to cooperate. Defendant asked Plai ntiff to return the fu nds paid. Plaintiff declined. So Plaintiff and her counsel remain in possession of the $250,000, despite losing on all three affirmative claims against Defendant at trial. And Defendant does not have an express jury finding that Plaint iff failed to cooperate , despite its request for one. After the district court entered judgment for Defendant, Plaintiff appealed several of the district court’s rulings, in cluding its denial of the motion for summary judgment. Post-judgment, Defendant sought to amend its answer to add counterclaims to obtain a modified court judgment that woul d order Plaintiff to return the $250,000 that Defendant paid under the reservation of rights. The district court denied9 Defendant’s motion, determin ing that it lacked jurisdic tion to address the issue because Plaintiff had filed he r notice of appeal. Alterna tively, the district court determined that it would not have allowe d Defendant to amend its answer. It reasoned the jury could have found that Defendant acted reasonably, properly investigated the claim, and properly paid Plaintiff the $250,0 00 for her injuries without finding that she had failed to c ooperate or had breached her contractual obligations. Defendant filed an appeal on this issue. Also post-judgment, the Clerk of Court fo r the United States District Court for the District of Colorado taxe d costs in the amount of $16, 247.21 against Plaintiff. Defendant sought review of the Clerk’s award, arguing that the Clerk erred in refusing to tax expert fees above the $40 pe r day witness appearance fee. Defendant argued that because it had se rved Plaintiff with an o ffer of judgment, which she refused, it was entitled to f ees under Colo. Rev. Stat. § 13- 17-202 because she did not recover a judgment in excess of the offer. The districtcourt disagreed, stating the $250,000 reservation of rights payment ef fectively amounted to a judgment. Defendant filed a second appeal on this issue.
II. We first address Plaintiff’s appeal—No. 19-1270—which presents five issues for review. First, whethe r the district court erred in failing to grant summary judgment for Plaintiff on either the failure- to-cooperate defense orPlaintiff’s breachof-contract claim. We review the distri ct court’s denial of summary judgment de novo. Wilson v. Union Pac. R.R. Co., 56 F.3d 1226, 1229 (10th Ci r. 1995) (citation10 omitted). Second, whether the district court erred in its interpretation of the policy’s failure-to-cooperate language. We review a district court’s inte rpretation of policy language de novo. Lexington Ins. Co. v. Precision Drilling Co., L.P., 951 F.3d 1185, 1194 (10th Cir. 2020) (citation omitted). Thir d, whether the district court erred in allowing Defendant to present its “set-up” defense theory . We review evidentiary rulings for abuse of discre tion. Cavanaugh v. Woods Cross City, 718 F.3d 1244, 1249 (10th Cir. 2013) (citation omitted). Fourth, whether th e district court erred in excluding certain evidence under a theory of mediation privilege. We review a district court’s rulings on motio ns in limine for abuse of di scretion. Id. And fifth, whether the district court erred in allowing Defendant to withdraw its stipulation that it owed Plaintiff some amount of UIM bene fits. District courts have “broad discretion in determining whether to hold a party to a stipulati on.” Wheeler v. John Deere Co., 935 F.2d 1090, 1098 (10t h Cir. 1991) (citation omitted). A. Plaintiff argues that the district court erred in denying her motion for summary judgment and motion for judgment as a matt er of law on Defend ant’s failure-tocooperate defense or Plaintif f’s breach of contract claim. We first address whether Plaintiff preserved this issue because of her failure to make a post-judgment motion for judgment as a matter of la w and whether we can hear th e appeal of the denial of her summary judgment motion after a trial on the merits. Because we determine that we have jurisdiction to review a portion of the denial of the summary judgment motion, we next turn to whether an insu rer can, under Colorado law, make a payment11 of benefits under a reservation of the right to claw back the payment. And, if so, whether that payment constitutes a confessi on of an insured’s breach of contract claim so that it moots an affirmative defense to that claim. Third, we discuss Plaintiff’s argument that Defendant failed to show that it was prejudiced by her alleged failure to cooperate. We then address Plaintif f’s contention that because no policy provision required her to provide estimates of surgi cal costs and future wage loss, her conduct did not violate a specif ic policy provision and Defendant cannot allege failure to cooperate. Fifth, we turn to whether Colorado law required Defendant to give Plaintiff notice of its in tent to assert the cooperation defense, the basis for that defense, and the opportunity to cure. Sixth, we discuss whether Defendant failed to plead it s affirmative defense with pa rticularity in violation of Federal Rule of Civil Proce dure 9(c). Finally, we addr ess Plaintiff’s argument that the district court’s decision to allow Defe ndant to present the failure-to-cooperate defense and instructing the jury on the defense was not harmless. 1. “Federal Rule of Civil Procedure 50 sets forth the procedural requirements for challenging the sufficiency of the evidence in a civil jury trial and establishes two stages for such challenges—pr ior to submission of the case to the jury, and after the verdict and entry of judgment.” Unitherm Fo od Sys., Inc. v. Swift-Eckrich, Inc., 546 U.S. 394, 399 (2006). Plai ntiff challenged the sufficie ncy of the evidence under Rule 50(a) prior to submission of the case to the jury. The di strict court denied Plaintiff’s motion. Plaintif f, however, failed to make a motion under Rule 50(b) to12 renew her challenge to the su fficiency of the ev idence after the jury verdict and entry of judgment. Defendant conte nds Plaintiff failed to preser ve her ability to appeal the denial of her motions for summary judgmen t and directed verdict by not filing a postjudgment Rule 50(b) motion. We agree. Without a Rule 50(b) motion, we lack the power to direct the district court to enter judgment contrary to the one it permitted to stand. Id. at 400–01 (citing Cone v. W. Va. Pulp & Paper Co., 330 U.S. 212 , 218 (1947)); see also Copar Pumice Co., Inc. v. Morris, 639 F.3d 1025, 1030 (10th Cir. 2011) (stating that a party cannot appeal its entitlement to judgm ent as a matter of law unl ess that party renews its motion under Rule 50(b)). Thus, Defendant correctly argues that Plaintiff cannot appeal the district court’s deni al of her Rule 50(a) motion. Plaintiff contends that “w ell-established law” suppor ts the proposition that a party may appeal rulings on Rule 50(a) mo tions based on the interpretation of legal questions. But the cases she cites for that proposition—Copar Pumice Co., Inc., 639 F.3d 1025 and Haberman v. Hartford In surance Group, 443 F.3d 1257 (10th Cir. 2006)—state that summary j udgment, not a Rule 50(a) mo tion, provides the only way to preserve these “purely lega l questions.” So we look not to her Rule 50(a) motion, but to the summary judgment proceeding. A party generally may notappeal a district court’s denial of a summary judgment mo tion. Ortiz v. Johns on, 562 U.S. 180, 184 (2011). But when the parties do not dispute the material facts a nd the district court bases its denial of summary judgment on it s interpretation of a purely legal question,13 a party may appeal such a decision afte r a final judgment. Haberman, 443 F.3d at 1264 (citations omitted). Our jurisdiction turns on whether the district court de nied the summary judgment motions on purely legal grounds. Although the district court identified various genuine issues of material fact in denying summary judgment, Plaintiff contends that the district court made fi ve determinations as a matter of law: (1) Defendant permissibly made a payment s ubject to a reservation of rights that did not render moot, waive, or foreclose its failu re-to-cooperate defens e; (2) a jury could reasonably find that Plaintiff had breached the general contr actual obligation of cooperation without specific policy language requiring Plaintiff to provide the estimated cost of future medical treatme nt and lost wages; (3) Defendant had no requirement to provide notice and opportunity to cure; (4) Plaintiff’s alleged conduct constituting the failure to cooperate coul d constitute substan tial and material prejudice; and (5) Defendant pleaded the fa ilure-to-cooperate defense with sufficient particularity. As noted in the previous paragraph, we have jurisdiction to review purely legal issues the district court d ecided on summary judgment. Haberman, 443 F.3d at 1264. For the reasons discussed be low, we conclude each issue, except for the second, constitutes a purely legal issue we may review. We now turn to the merits.14 2. Colorado has not spoken on the issue of whether an insurer may make a payment to an insured subject to a reservation of rights and then seek to claw back or recoup its payment. We hold that under Colorado law an insurer may do so. The district court relied on our previ ous recognition that, under Colorado law, an insurer has an entitlement to reimbursement of defense costs if a court determines that insurer had no duty to defend. Valle y Forge Ins. Co. v. Health Care Mgmt. Partners, Ltd., 616 F.3d 1086, 1091–92 (10t h Cir. 2010); see also Mt. Hawley Ins. Co. v. Casson Duncan Constr. Inc., 409 P. 3d 619, 623 (Colo. App. 2016) (citing Valley Forge). In relying on that holding, th e district court did notblaze a new trail. Indeed, the District of Colorado previously extended our holding in Valley Forge to determine that “an insurer ma y pay an insured under a rese rvation of rights and then seek to recoup its payment.” Auto- Owners Ins. Co. v. Summit Park Townhome Ass’n, No. 14-cv-3417, 2016 WL 1321507, at *4 (D. Colo. April 5, 2016) (citing Valley Forge). And this extension is a natu ral application of the rule we divined in Valley Forge. We agree with the district court—a nd predict the Colorado Supreme Court would hold—that a reservation of rights does not destroy the insured’s rights or create new rights for the insurance compa ny. Rather, the reservation of rights “preserves that to which the parties had originally agreed .” Mut. of Enumclaw v. Harvey, 772 P.2d 216, 220 (Idaho 1989). I ndeed, just like the policy at issue in Valley Forge, the policy here contains no c ontractual language refe rencing a right to15 recoupment. Instead, the po licy language provides that if Defendant and the insured do not agree on the right to benefits and the amount payable, a court of competent jurisdiction will resolve the di sagreement. The policy also sets forth that Defendant has a right to decline to pa y a claim where the insured causes material prejudice to Defendant by failing to cooperate. And Defe ndant also has the right to have that dispute settled by a court. Thus, Defendant had the right to pay Pl aintiff subject to a reservation of rights and to claw back that payment s hould a court determine that Plaintiff had no entitlement to the payment. Because we answered the prior question in the affirmative, we now turn to whether that payment constitutes a confession of Plaintiff’s breach of contract claim so that it moots Defendant’s affirmative failure-to-cooperate defense to that claim. We hold that it does not. Defendant made clear when it paid Plaintiff the policy limits that it reserved the rightto claw back the payment. Cases Plaintiff cites that conclude the opposite lacked a reservation of rights letter. See Peden v. State Farm Mut. Auto. Ins. Co., No. 14-cv-982, 2018 WL 3496735 (D. Colo. July 20, 2018) (holding that the insurer could not assert a cooperation defense where it paid the entire insured’s UIM claim without a reserva tion of rights). Here, the reservation of rights letter shows that Defenda nt did not confess Plaintiff’s breach of contract claim. Nor does the fact that Defendant eventu ally completed its investigation moot Defendant’s affirmative fail ure-to-cooperate defense. In Colorado, an insured’s failure to cooperate breaches the contract if the insurer suff ers a material and substantial disadvantage. St ate Farm Mut. Auto. Ins. Co . v. Secrist, 33 P.3d 1272,16 1275 (Colo. App. 2001) (citation omitted). Often, the prejudice from a failure to cooperate manifests in the in surer’s failure to complete an investigation. But the prejudice here does not result from De fendant’s inability to complete an investigation. Rather, the alleged failure to cooperate forced Defendant to defend a bad faith suit. The Colorado Court of App eals, albeit in an unpublished decision, acknowledged this type of prejudice. See Windhorst v. State Farm Mut. Auto. Ins. Co., No. 11CA1045, 2012 WL 1884652 (Colo. App. May 24, 2012) (providing that the insurer receiving medical records did not cure the prejudice because by that time the insurer was defending agains t claims based on its allege d failure to timely process and pay UIM benefits); see also Pilgrim v. State Farm Fire & Cas. Ins. Co., 950 P.2d 479, 486 (Wash. Ct. App. 1997) (concludi ng insurer suffered prejudice when insured failed to provide financial information in connection with a first party claim because insurer could not evaluate the validity of the insurance claim without financial documents from insured). Quite simply, unde r this theory, had Plaintiff cooperated, Defendant would have had the relevant information to make an informed offer prior to Plaintiff’s filing of the bad faith suit. Because Defendant claimed she did not, it asserted that it could not make such an offer and had to litigate a bad faith claim. Thus we agree with the district court that Defendant’s payment of the claim, subject to a reservation of rights, did not moot, wa ive, or extinguish Defendant’s failure-tocooperate defense.17 3. Plaintiff contends that Defendant failed to demonstrate that it was prejudiced by Plaintiff’s alleged failure to cooperate. As discussed in the previous section, the district court properly held th at a failure to cooperate that results in a bad-faith case can be prejudicial. Plaintiff couched whet her prejudice exists as a legal question, arguing that in allowing the jury to de termine whether Defendant was prejudiced materially, the district court impliedly rule d that the conduct that Defendant claimed constituted a failure to cooperate could resu lt in substantial and material prejudice. But rather than argue the la w, Plaintiff’s briefing focu s on the sufficiency of the evidence. Plaintiff argues th at the facts presented to th e district court at summary judgment and at trial could no t possibly support a finding of prejudice. The district court held in its order denying summary judgment that a jury reasonably could find that Plaintiff complied with th e terms of the policy, but al so held that a jury could find that she did not comply with those term s. Plaintiff contes ts the latter. For instance, she asserts that no evidence showed that Plaintif f or her counsel withheld any material information, that no evid ence showed Defendant’s inability to do a reasonable investigation, and that evid ence overwhelmingly demonstrated that Plaintiff did not prevent Defendant from inve stigating Plaintiff’s claim, particularly the cost of the future surgery or associatedfuture wage loss—all of which go to the sufficiency of the evidence. Indeed, whether Plaintiff’s conduct c onstituted noncoope ration presented a question of fact and of the sufficiency of the evidence. And perhaps the evidence of18 noncooperation or of prejudice in this case was so lack ing that the district court erred in failing to grant summary judgment or Pl aintiff’s Rule 50(a) motion. But we are powerless to make that determination because of the procedural posture of this case. Unitherm, 546 U.S. at 405. We will not second guess the district court’s determination. As we discussed earlier, Plai ntiff’s failure to make a Rule 50(b) postjudgment motion for judgment as a matter of law precludes her sufficiency of the evidence argument on appeal. Id. 4. Plaintiff next argues that no policy provi sion required her to provide estimates of future surgical costs and future wage loss. That lack of language, Plaintiff contends, means her conduct c ould not have violated a spec ific policy provision and, therefore, Defendant cannot as sert a failure-to-cooperate de fense. But we conclude the district court did not err in determini ng that a jury could reasonably find that Plaintiff failed to comply w ith the cooperation clause. Plaintiff contends the policy explicitly required her only to provide a release authorization, which she did, and to atte nd a medical examination if requested, which Defendant did not. Plaintiff relies on a Colo rado Court of Appeals case to argue that the district court and Defendant have held he r to a standard of co nduct not set forth in or required by the policy—Ahmadi v. Alls tate Insurance Company, 22 P.3d 576 (Colo. App. 2001). In Ahmadi, the insure r requested examinations under oath of three insureds, in accordance with the policy’s requirement that they submit to such an examination upon request. Id. at 577. The policy also included a standard19 cooperation clause. Id. The insureds, not a ll English speakers, appeared together for the examinations and refused to allow the insurer to separa te them from one another. Id. at 577–78. The insurer insisted on sepa ration to no avail, and the examinations did not take place. Id. at 578. Becau se they would not submit separately to examination, the insurer alleged failure to cooperate. Id. On appeal, the insureds argued that by showing up together, they complied with the policy language. The Colorado Cour t of Appeals agreed. In reaching that conclusion, the court held th at the policy “[did] not mandate that the examination to which a claimant must submit shall be held outside the presence of other claimants.” Id. The Colorado Court of Appeals held th at “we must give effect to the plain meaning of the policy terms” and “we are no t at liberty to rewr ite the policy.” Id. (citations omitted). Thus, “had [the in surer] desired to impose [separation of examinees], it could have done so by an e xpress term in the policy.” Id. (citation omitted). So the court reject ed the insurer’s claim that the refusal to sequester violated the examination clause. Id. at 579. The Ahmadi court also rejected the insu rer’s argument that fa iling to submit to sequestration violated the coope ration clause. It held th at “because the policy here contains a requirement for an examin ation under oath, but does not impose an additional requirement that the examination be held separately and without any other claimants being present, we conclude that the trial cour t erred in holding that the claimants had breached the cooperation clause.” Id. at 580. The court’s holding that the insureds had not violated the cooperation clause was, therefore, because they had20 not violated the examination clause. Plaint iff ignores the fact th at her case does not involve a second, more specific clause , such as an examination clause. Defendant’s cooperation defens e arises from Plaintiff’ s conduct, not the failure to provide information alone. The evidence shows that Plaintiff’s counsel agreed to provide this information, never refused De fendant’s requests for the information, and led Defendant to believe she was cooperating with the investigati on. We agree with the district court that Defenda nt could have reasonably reli ed on Plaintiff’s promises to provide information and that Plaintif f’s subsequent failur e to provide that information without informing Defendant th at she refused to do so could constitute noncooperation. The district court did not err by sending th e question to the jury.
5. Plaintiff next contends that both the law and Defendant’s policy required that Defendant provide her notice of its intent to assert th e cooperation defense and the basis for that defense as well as a chance to cure before it asserted she failed to cooperate. But Plaintiff cite s no Colorado law to support her contention. Instead, Plaintiff cites a Tenth Circuit case appl ying Oklahoma law and a dissent from the Colorado Supreme Court. The Tenth Circuit case—State Farm Fire and Casualty Insurance Company v. Payne, 982 F.2d 529 (10th Cir. 1992) ( unpublished table decision)—involved an insured’s pre-suit failure to cooperate, of which the insurer knew before the suit. Here, Defendant did not know about Plaintiff’s failure to cooperate before the suit because Plaintiff, in Defendant ’s words, “presented a pret ense of cooperation.” Thus21 the prejudice to Defendant did not manife st, and the defense did not arise, until Plaintiff sued. Th e Colorado case—Francom Building Corporation v. Fail, 646 P.2d 345 (Colo. 1982) (en banc)—is likewise inapposite. Plaintif f cites the dissent in that case, which interpreted and applied the no tice requirement of Colorado’s forcible entry and detainer statute. Plaintiff ac knowledges that Fail did not involve insurance law but argues that the Colorado Supreme Court has imposed notice and opportunity to cure requirements in other forfeiture contex ts, so it would in th is context as well. Maybe so. But Plaintiff overlooks Defenda nt’s argument that inclusion of the defense in the answer timel y and sufficiently put Plai ntiff on notice because the prejudice of the failure to cooperate did not manifest until after Pl aintiff sued. Thus, the defense did not apply until after Plaintiff sued. As to the policy, trial testimony show ed that Defendant provides insureds notice by a reservation of rights letter wh en it learns of a potential failure to cooperate before suit is fi led. But when an insured sues, Defendant provides such notice in a responsive pleading. Trial testimony also re vealed that the policy does not require a chance to cure. Rather, Defe ndant may provide such an opportunity. As we discussed above, in Colorado, an insured’s failure to cooperate breaches the contract if the insurer su ffers a material and substantia l disadvantage. Secrist, 33 P.3d at 1275. Here, the distri ct court held that “a jury could reasonably conclude that [Defendant] suffered a material and substantial disadvantage by having its investigation delayed and bei ng sued for bad faith as a re sult.” We agree with the district court. The prejudice from Plainti ff’s failure to cooperate did not arise until22 Plaintiff filed the suit. And at that point , Defendant could not po ssibly give Plaintiff a chance to cure. The only po ssible way to provide notice after suit is to respond in a pleading. No authority supports Plaintiff’s positi on. Here the suit itself was the prejudicial result of Plainti ff’s failure to cooperate. The district court did not err in determining that neither the law nor the po licy required Defendant to provide pre-suit notice and opportunity to cure. 6. We now turn to Plaintiff’s contention that Defendant failed to plead the affirmative defense with particularity. Plaintiff argues Defendant violated Rule 9(c)’s command that when denying a condition precedent has occurred or been performed, a party must do so with partic ularity. But Plaintiff’s argument assumes that a cooperation defense is a conditions-precedent defense. We need not determine whether a cooperation defens e is a conditions-precedent defense because whether Rule 9(c)’s standard or the general pleading standard for affirmat ive defenses applies is immaterial here. And that is because, put plainly, Defendant insufficiently pleaded its affirmative defense in fa iling to identify what policy provision Plaintiff violated or how she had violated the provision. Gi ven that, the material questions we must consider are whether Plaintiff waited too lo ng to move to stri ke the affirmative defense and whether the district court co rrectly rejected Plaintiff’s arguments— questions we answer in the affirmative.23 Plaintiff never moved to strike th e defense under Rule 12(f)—the proper vehicle to challenge the pleading of a defe nse. Plaintiff had a chance to conduct discovery into the defense. And Plaintiff had the ability to fully litigate the defense at summary judgment and at tr ial. Courts, both in this Ci rcuit and in others, regularly decline to entertain Rule 9 arguments at the summary j udgment stage. See Bank of Albuquerque, N.A. v. Dykes, Civ. No. 07-44, 2008 WL 11417171, at *2 (D.N.M. Jan. 16, 2008) (“the Court nevertheless d eclines to rule against Defendants on the basis of this alleged procedural shortcom ing. Plaintiff did not move to strike Defendants’ answer on the pleadings, or as k for a more particular statement of allegations.”); Burton v. R.J. Reynolds Tobacco Co., 181 F. Supp. 2d 1256, 1262 n.5 (D. Kan. 2002) (“To the extent defendants are suggesting that plaintiff’s fraudulent concealment claim should be stricken for failure to comply w ith Rule 9(b), the court’s rejects this belated challenge.”); Davsko v. Golden Ha rvest Prods., Inc., 965 F. Supp. 1467, 1474 (D. Kan. 1997) (“ Here, defendants answered plaintiff’s complaint without raising any objection under rule 9(b). Defendants cannot argue almost a year later that pl aintiff failed to plead fraud with particularity.”); United Nat. Records, Inc. v. MCA, Inc., 609 F. Supp. 33, 39 (N.D. Ill. 1984) (“Defendants have had a sufficient opportuni ty to respond to plaintiffs’ charges as contemplated by Rule 9(b). Accordingly, defendants’ cont entions regarding plaintiffs’ failure to comply with Rule 9(b) have been waiv ed.”); Power Application & Mfg. Co. v. Moscow Agri-Indus., Inc., No. 86-1656-PFK, 1992 WL 363684, at *4 (D. Kan. Nov. 10, 1992) (the plaintiff, in its motion for summary judgme nt, “originally argued that24 [the defendant’s] complaint does not me et the standards of the Federal Rules by pleading fraud with any particularity.” In response, the defendant “correctly pointed out that by waiting to make this motion until after the pretrial order and much discovery, [the plaintiff] has effectively wa ived any right to obtain dismissal of the fraud claim on procedur al grounds.”). We agree with Defendant that Plaintiff rais ed the issue too late in the process. She suffered no prejudice and the district cour t did not err in refusing to consider her belated arguments. Failure to plead with specificity is not a matter for summary judgment.
7. Finally, Plaintiff argues th at we must remand this case because the district court erred in permitting Defendant to pr esent the failure-to-cooperate defense and that instructing the jury on that defense wa s not harmless. She a sserts that the court instructed the jury on the elements of a failure to c ooperate and to consider that defense as to all claims, wh ich resulted in a smear campa ign against Plaintiff that lasted throughout the trial. Plaintiff posits that De fendant supported none of its argument surrounding the failure to coope rate by competent evidence of facts showing a legally viable failure to cooperate . This argument, too, must fail. We previously concluded that th e district court did not err in any of the above legal rulings. Thus the district c ourt did not err in allowing Defe ndant to present its failure to cooperate defense. We al so concluded that Plaintiff’s failure to make a Rule 50(b) motion precludes us from conducting any evid entiary review for su fficiency at trial25 or in search of a genuine issue of fact at summary judgment . Thus, we hold the district court did not err in refusing to gr ant summary judgment in Plaintiff’s favor on either Defendant’s affirmative coopera tion defense or on Plaintiff’s breach of contract claim. Because we find no error, we do not c onsider Plaintiff’s argument that the error was not harmless.
B. Plaintiff also argues that the district court erred in its interpretation of the policy’s failure-to-cooperate language. She as serts that the provision can apply only to third-party claims, not firs t-party claims, and that the relevant policy provision is ambiguous. The district cour t did not address these argum ents. Defendant contends that Plaintiff did not preserve this issue for app eal. We agree that Plaintiff raises these arguments for the first time on appeal. Therefore, the district court did not have the opportunity to rule on them. We rarely consider an issue raised for the first time on appeal. TeleCommc’ns, Inc. v. C.I.R., 104 F.3d 1229, 12 32 (10th Cir. 1997) (c itations omitted). The reasoning is simple enough. Review of issues partie s did not raise below would require “additional evidence gathering and findings; would undermine the need for finality in litigation and conservation of judicial resources; wo uld often have this court hold everything accomplished below fo r naught; and would often allow a party to raise a new issue on appeal when that pa rty invited the alleged error below.” Id. And our refusal to consider these newly ra ised issues “is part icularly apt when dealing with an appeal from a grant of summa ry judgment.” Id. At that point, the26 district court considers only opposing legal theories—not f actual disputes. Id. We are not a second-shot forum. Id. at 1233. Thus, we require a party to present an issue to the district court before raising that issue on appeal. Id. But what about vague, arguable references to a point in the district court proceedings? We have held that such passing references do not preserve an issue on appeal. Id. We will not a ddress new arguments on appeal regardless of “whether an appellant is attempting to raise ‘a bald face d new issue’ or ‘a new theory on appeal that falls under the same general category as an argument presen ted at trial.’” McDonald v. Kinder-Morgan, Inc., 287 F3d 992, 999 ( 10th Cir. 2002) (quoting Lyons v. Jefferson Bank & Trust, 994 F. 2d 716, 722 (10t h Cir. 1993)). So we turn to whether Plaintiff preser ved her argument. In Plaintiff’s opening brief, she states that she preserved this argument at oral argument on her summary judgment motion. That oral argument lasted about two hours. And Plaintiff raised the ambiguity issue one tim e, arguing, “Allstate is relying 100 percent upon a cooperation clause that does not apply in a first party case and it does not apply in a first party case because it’s ambiguous, b ecause it’s overbroad and it doesn’t make any logical sense.” In contex t, the discussion before and after that statement centered on interpreting Windhorst and the definiti on of prejudice—not on the ambiguity of the provision. So the distri ct court’s failure to rule on ambiguity, yet make a ruling on Windhorst and whether De fendant had argued a cogn izable prejudice, is no surprise. This mere menti on in the district court oral argument does not preserve either the question of the a pplicability of the provision or of its ambiguity. See Folks27 v. State Farm Mut. Auto. Ins. Co., 784 F.3d 730, 741 (10th Cir. 2015) (providing that “vague, arguable references to a point in the district court proceedings do not preserve the issue on appeal” (q uoting Lyons, 994 F.2d at 721)). Only after Defendant argued that Plaintiff did not raise this argument in her eightythree-page summary judgment briefing did Plaintiff cite the re cord in her appellate reply brief. Plaintiff raised her applicability argument in a footnote inher summary judgment motion: This general cooperation language is a pplicable only to third party claims where an insured is being defended by the insurer – not in first party claims where the insured is making a claim to her insurer, as is the case here. . . . The absurdity that would result in applying the general cooperation clause language in a first party claim is read ily apparent when c onsidering that the clause requires the insured to cooperate with the insurer in the insurer’s attempts to “settle” the claim – read literally, this would require the insured to “accept” any “settlement offer” made by the insurer, as refusing to do so would not assist the insure r in settling the claim. This would be an absurd result. (internal citation omitted). In the introductionof her response to Defendant’s motion for summary judgment, Plaintiff argued: The Allstate narrative in fact shows a cour se of conduct of an adjuster making what appear to be “social” requests for information, which A llstate then turns into a claim of a contract violation, resulting in forfeiture, based upon a “general” duty to cooperate with an “investigation”, in a cooperation section clearly intended to apply to 3rd part y liability claims (cooperate in the “defense” of lawsuits), and not the specific first-party cooperation requirements such as providing me dial authorizations and medical examinations. Allstate’s extremely over broad interpretation and assertion of cooperation clause violations vi olates Colorado public policy. Later in the same respon se, while discussing her sp ecific-provision argument, Plaintiff recites, verb atim, the footnote quoted above. Finally, in her reply in support28 of her motion for summary judgment, Plain tiff said, “an insurer cannot deny a claim for failure to cooperate wher e the alleged failure is not in violation of a specific nonambiguous requirement of the insurance po licy, and only then after a reasonable request.” But Plaintiff r ecited that proposition of la w for her specific-provision argument, addressed below. She did not specifically argue th at the provision was ambiguous. We conclude Plaintiff forfeited this argument. Her passing reference to applicability and ambiguity at oral argument before the district c ourt did not preserve this issue. Nor did her single footnot e and two sentences of argument in her summary judgment briefing. These arguments , raised before the district court in a perfunctory and undeveloped ma nner, parallel the kind of arguments we have refused consistently to take up in the past. See Folks, 784 F.3d at 741 (noting that “minimal development of an issue in the district c ourt could well result in forfeiture” (citation omitted)). Because Plaintiff forfeited this argument by not raisi ng it before the district court, we review for plain error. Richis on v. Ernest Grp., In c., 634 F.3d 1123, 1128 (10th Cir. 2011) (Gorsuch, J.). Plaintiff, however, did notargue for plain error in her brief, even in the a lternative. Our “long-standing prac tice has been to review newly raised (but not waived) legal arguments under what substantively amounts to (and what we have more recently described as) the plain error standard.” Id. To be sure, “[a]ffording plenary appellate review to ne wly raised legal theories would do much to undermine this adversarial and appellate order.” Id. at 1130.29 Plaintiff has not tried to show how he r new legal theory satisfies the plain error standard. “And the failu re to do so—the failure to argue for plain error and its application on appeal—surely ma rks the end of the road fo r an argument for reversal not first presented to the di strict court.” Id. at 1131 (c itation omitted). As a result, we will not consider this issue. C. The district court allowed Defendant to present a theory of the case that Plaintiff’s conduct “set-up” Defendant for a bad-faith laws uit. Plaintiff argues the district court erred becau se this argument constitute d an unalleged affirmative defense not recognized by Colorado law. 2 She contends that under Colorado law, an insured’s motivations or financ ial interests are i rrelevant and do not present a defense for an insurer alleged to ha ve breached its duties to the insured. She argues that Defendant’s theory constitutes “an accusati on of deceit sounding in fraud” and that Defendant was trying to make the case for insura nce fraud. Defendant, on the other hand, asserts that this “set- up” theory is not an affirm ative defense. Rather, the argument is a theory to explain Plaintiff’ s and her counsel’s conduct and the pre-suit interactions between the par ties. We agree with Defenda nt. The theory is not an

2 Plaintiff also again relies on Rule 9( b)’s particularity requirement for an allegation of fraud and her alle gation that Defendant did notraise this defense until a proposed final pretrial order in April 2019, right before tr ial. Plaintif f asserts she was not able to investigate the grounds fo r the defense or know of the basis for it until that time. But Defendant thoroughly alleged this defens e in a November 2017 proposed final pretrial orde r, which gave Plaintiff enoug h time to conduct discovery into the theory, including through her de position of Defendant’s Rule 30(b)(6) representative.30 official “set-up” defense butis simply Defendant’s pro ffered motive for Plaintiff’s failure to cooperate. Defendant’s “set-up” theory is not an affirmative defense. We define an affirmative defense as a “def endant’s assertion of facts and arguments that, if true, will defeat the plainti ff’s . . . claim, even if all the allegations in the complaint are true.” Black’s Law Dictiona ry at 451 (8th ed. 2004). Defendant did not argue its theory of the case was dispositive. We agr ee with the district court that Defendant’s setup argument—rather than constituting a defense to Plainti ff’s claims—explained its theory of the case for why Pl aintiff failed to cooperate. Plaintiff directs us to cas e law to support her position. She cites Caldwell v. Wal-Mart Stores, Inc., 229 F. 3d 1162, at *4–5 (10th Ci r. 2000) (unpublished table decision), for the proposition that evidence, ar gument, and references to a plaintiff’s financial motivation to bring a lawsuit are inappropriate ab sent evidence of fraud. But in that case, the plaintiff had promised that he would gi ve his partners in a failed business some of the money from the suit against Wal-Mart. The court disallowed the evidence because it was irrelevant and unfairly prejudi cial. Id. at *5. Wal-Mart did not offer the evidence as a theory of its defense but as an attack on the plaintiff’s credibility and characte r. Plaintiff also cites Miller v. Byrne, 916 P.2d 566, 576 (Colo. App. 1995), for the proposition that an insured’s motivations or financial interests are irrelevant to wh ether an insurer fulfilled it s non-delegable duties owed in good faith to its insured. But that is not what Miller holds. Th e court said that the motivation or intent was not le gally material or logically re levant on this record. Id.31 Miller does not foreclose the idea that an insurer could put forth a financial motivation as their th eory of the case regarding why an insured failed to cooperate. Plaintiff also references Heritage Vill age Owners Association, Inc. v. Golden Heritage Investors, Ltd., 89 P.3d 513, 518–19 (Colo. A pp. 2004), for the proposition that a court should not permit the jury to learn of the consequen ces for the defendant from statutory trebling penalties and that such information could create unfair prejudice. But the Colorado Court of Appeals did not draw a bright line rule in that case. Rather it stated, “we do not deem itnecessary to determin e whether a jury may never be advised of treble damages.” Id. at 519. Its conclusion simply was that the trial court did not err by declin ing to instruct the jury of the trebling provision. Id. Plaintiff’s cited cases lend no support to her contenti on that Defendant’s “setup” theory constitutes an affirm ative defense. Thus, we hol d the district court did not err in allowing Defendant to present its theory of the case to the jury.
D. We next address Plaintiff’s contention th at the district court erred in excluding certain evidence related to settl ement of the claim. We re view evidentiary rulings for abuse of discretion and the tr ial court’s preliminary factual findings relating to the admission of evidence for clear error. United States v. Williamson, 53 F.3d 1500, 1517 (10th Cir. 1995) (cit ations omitted). Defendant authorized a $250,000 settlement before mediation and later drafted a $250,000 ch eck that its counsel never provided Plaintiff. Defendant moved in limin e to exclude the entries in the claim log related to the mediation a nd the check, the original $250, 000 check, and the letter32 from the accounting departmentasking why Plaintiff had not cashed the check. The district court held an ev identiary hearing on the issu e and excluded the evidence under Federal Rule of Evidence 408 and 403. The district court reasoned that Defendant prepared the entries for and in th e context of the media tion and, therefore, the check and letter were “so causally conn ected” to the mediation that introduction would unduly confuse the jury. We find no error in the district c ourt’s ruling. Rule 408 provides that statements made in compromise negotiation are not admissible to prove or disprove the validity or amount of a di sputed claim. And the record the district court made at the evidentiary hearing provide s ample evidence that Defenda nt created the entries in the context of and in preparation for me diation. Indeed, Defendant created the entries two days before and the day of th e mediation and the entries reference the mediation. The district c ourt did not commit clear error in its factual determination that Defendant created the entries for media tion. The district court likewise did not abuse its discretion in granting Defendant’s motion to exclude the ensuing check and letter. The district court reasoned that Defendant could explai n the documents only while discussing the mediation. Thus, Defendant would have to explain that it issued the documents because it authorized $250, 000 to settle the litigation. Plaintiff argues that she did not seek to offer the evidence to prove the amount of her damages, but to prove Defendant’s knowledge that her da mages exceeded the available UIM limit, that it chos e not to pay the benefits it knew that it owed to gain some strategic advantage, and Defendant’s continuing ba d faith. True, Rule 408 does33 not exclude evidence offered for another pu rpose. And evidence of a party’s bad faith may fall under another purpose. But we do not review this issue de novo. We have said that “when the issue is doubtful, the better practice is to exclude evidence of compromises or compromise offers.” Bradbury v. Phillips Petroleum Co., 815 F.2d 1356, 1364 (10th Cir. 1987). The di strict court conducted an evidentiary hearing and determined that Rule 408 ba rred admission of the evidence because Defendant made the entries abou t valuation of the claim in preparation for mediation. See Eisenberg v. Univ. of N.M., 936 F.2d 1131, 1134 (10th Cir. 1991) (explaining that Rule 408 is designed to encourage sett lement of disputes). The district court’s decision was reasonable, and we conclude it did not abuse its discretion in barring the evidence pursuant to Rule 408. But the district court also believed that admission of th e letter and check would confuse the jury from the relevant is sues in the case and also barred it from coming into evidence under Rule 403. Agai n, the district court’s decision was reasonable and it did notabuse its discretion. Indeed , the “risks of prejudice and confusion entailed in rece iving settlement evidence are such that often . . . the underlying policy of Rule 408 require[s] exclusion even when a permissible purpose can be discerned.” E.E.O.C. v. Gear Petr oleum, Inc., 948 F.2d 15 42, 1546 (10th Cir. 1991) (alterations in original ) (citation omitted). See also Weir v. Fed. Ins. Co., 811 F.2d 1387, 1395 (10th Cir. 1987) (“A lthough Rule 408 does not prohibit the admission of evidence of the circumstan ces surrounding a settlement to prove something other than liability—such as voluntariness—many of the same concerns34 about prejudice and deterrence to settleme nts exist regardless of the purpose for which the evidence is offered” ). Thus, we hold the distri ct court did not abuse its discretion in excluding the evidence under Rules 408 and 403. 3
E. In the scheduling order, Defendant sti pulated that it owed Plaintiff some amount of UIM benefits. Specifically, “Allsta te has determined th at Ms. Cribari is owed compensation for her inju ries, damages and losses rela ted to the . . . collision under her underinsured motori st coverage.” This stipul ation did not make the final pretrial order. The district court ruled at trial that Pl aintiff could not introduce the stipulation to the jury. Plaintiff contends the district court erred. “[I]f a party waits until trial to withdraw s tipulations submitted in the pretrial order, the recital of facts ‘may be modified at the tria l only to prevent manifest injustice.’” In re Durability Inc., 212 F.3d 551, 556 (10th Cir. 2000) (quotin g United States v. Sommers, 351 F.2d 354, 357 (10th Cir. 1965)). “That standard comports with [Rule] 16, which mandates that pretrial orders ‘shall be modified only to prevent manife st injustice.’” Id. “If, however, the request to withdraw or amend the stipulation is made before significant prejudice to the other parties would result, promotes important equitable and legal considerations, and is not controlled by a rule of procedure, the party seeking to withdraw

3 In her reply brief, Plaintiff for th e first time raises the argument that Defendant waived any Rule 408 objections by introducing evidence of settlement negotiations and offers itself. But a party waives issues and arguments raised for the first time in a reply brief. Reedy v. We rholtz, 660 F.3d 1270, 1274 (10th Cir. 2011) (citation omitted).35 must simply show good reason for the request.” Id. (citati on omitted). See also Uranium Contracts Litigation, 570 F.2d 899, 902 (10th Cir. 1978) (holdi ng that, where later events “reveal[ed] a need for further discovery,” “we must hold that it woul d be inequitable to enforce an agreement ag ainst further questioning of [a ke y fact witness], thus closing the door to development of potentiallycritical facts.”); Fairfield De v., Inc. v. J.D.I. Contractor & Supply, Inc., 782 F. Supp. 2d 1205, 1211 (D . Colo. 2011) (finding that, where “[p]laintiffs’ recent conduct . . . has caused[defendant] to ques tion the foundation of [p]laintiffs’ claims and suggested that [d efendant] should look mo re closely at the damages,” the court should relieve the defendant of a stipulation as to the amount of damages). “Ultimately, ‘the district court is ve sted with broad discretion in deciding whether to enforce [the] parties[’] stipul ation or not.’” Lincoln v. BNSF Ry. Co., 900 F.3d 1166, 1188 (10th Cir. 2018) (alterations in orig inal) (quoting Miller v. Eby Realty Grp. LLC, 396 F.3d 1105, 1116 (10th Ci r. 2005)). “A court will not always enforce the terms of a stipulation in the ri gid manner that a cour t typically enforces the terms of a contract.” Id . “Even though a court may not overlook stipulations as a matter of course, no rule of law requires a court to base the resolution of the case on stipulations of the parties. ” Id. (quoting O’Connor v. City & Cnty. of Denver, 894 F.2d 1210, 1226 n.12 ( 10th Cir. 1990)). At the pretrial conference, the district court ruled that it would not read the stipulation at trial. The di strict court reasoned that Defe ndant no longer agreed to its previous stipulation based on Plaintiff’s a lleged failure to cooperate. The district36 court said that Plaintiff could ask about th e stipulation at trial, subject to potential objection. At trial, Plaintiff sought to introduce the stipulation and Defendant objected. The district court decided to ex clude the stipulation, stating that the statement was not probative. Moreover, the district court found that Defendant had an explanation for the change in positi on and allowing Plaintiff to introduce the stipulation would be overly confusing for the jury. The district court did not abuse its discretion in excluding Defendant’s stipulation from the original scheduling order. During lit igation, Defendant discovered information which altered it s position on the fact ual basis for the stipulation. Plaintiff’s intr oduction of the stipulation woul d require the jury to hear information about how parties enter into st ipulations, the various types of pretrial orders, the discovery process, and the d ecision-making process counsel employs. Ultimately, the stipulated fa ct was not probative because ev en if Defendant at first conceded it owed Plainti ff something, newly discove red evidence uncovered in discovery explained its change in position. Allowing the ju ry to hear the stipulation would have only confused the jury. The dist rict court did not abuse its discretion in excluding the stipulation.
III. We next address Defendant’s firs t appeal—No.19-1343—challenging the district court’s denial of Defendant’s motion for leave to amend or supplement its pleading and add counterclaims. We review the district court’s de nial of a motion for leave to amend for abuse of discretion. Zisumbo v. Ogden Reg’l Med. Ctr., 801 F.3d37 1185, 1195 (10th Cir. 2015) (citation omitted). But we review a district court’s ruling on a jurisdictional question de novo. FDIC v. Hulsey, 22 F.3d 1472, 1479 (10th Cir. 1994) (citation omitted). Following the jury’s verdic t, Defendant asked Plaintiff to return the $250,000 pursuant to the reservation of rights. Af ter Plaintiff refused, Defendant filed a motion for leave to supplemen t its earlier pleading to add counterclaims for replevin, unjust enrichment, breach of contract, and conversion. Although Plaintiff had filed its notice of appeal, Defendant argued its mo tion was timely because it filed it “mere days after the causes of acti on accrued.” Alternatively, De fendant said it sought to amend its pleading to conform to the eviden ce because the jury’s verdict necessarily found that Defendant had not breached the contract, did not unreasonably delay or deny the benefits, and had not breach ed the contract in bad faith. We begin our analysis with the premise that “a federal district court and a court of appeals should not a ttempt to assert jurisdiction over a case simultaneously.” Stewart v. Donges, 915 F.2d 572, 574 (10th Cir. 1990) ( quoting Griggs v. Provident Consumer Disc. Co., 459 U.S. 56, 58 (1982 )). A party filing a notice of appeal triggers “an event of jurisdictional signi ficance—it confers juri sdiction on the court of appeals and divests the di strict court of its control over those aspects of the case involved in the appeal.” Id. ( quoting Griggs, 459 U.S. at 58). The district court correctly determined that it lacked juri sdiction to decide Defendant’s motion. The fili ng of a notice of appeal gene rally divests the district court of jurisdiction over the is sues in the appeal. Lancaster v. Indep. Sch. Dist. No.38 5, 149 F.3d 1228, 1237 (10th Cir. 1998) (c itation omitted). The district court, however, “retains jurisdiction over ‘collatera l matters not involved in the appeal.’” Id. (quoting Garcia v. Burlington N.R.R. Co., 818 F.2d 713, 721 (10th Cir. 1987)). Defendant contends that the matters raised in its motion for leav e are not involved in Plaintiff’s appeal because th e proposed counterclaims ar ose only after, and because of, the final judgment. It argues that it became entitled to the funds under the reservation of rights only because of th e jury verdict and final judgment. We disagree with Defendant’s argument that its new claims are separate from the claims it asserted during the lawsuit. Indeed, Plaintiff’s appeal included the argument that the district court should not have allowe d Defendant to presen t the “failure to cooperate” defense to the jury . Plaintiff also appealed whether the district court should have included that defense in the ju ry instructions. Whether Plaintiff could retain the check is intertwine d with the issues Plaintiff raised in her notice of appeal and is not a collateral matter not involve d in the appeal. See Garcia, 818 F.2d at 721–22 (concluding a determinat ion of prejudgment interest was not a collateral issue where the plaintiff specifically asked perm ission to amend its complaint to include prejudgment interest, and the trial court gran ted that motion by amending the pretrial order, but the district court did not mention prejudgment inte rest in its final order and did not reserve the matter and the plaintiff did not ask for reconsideration but instead filed a notice of appeal). Th e district court did not err in its conclusion that it lacked jurisdiction to consider Defendant ’s motion for leave to amend.39 IV. Lastly, we address Defendant’s sec ond appeal—No. 19-1425—appealing a portion of the district cour t’s order denying Defendant’s motion for review of the Clerk’s costs and fee award. We review an award of co sts for abuse of discretion, but whether costs provisions a pply is a legal question we re view de novo. Marx v. Gen. Revenue Corp., 668 F.3d 1174, 1178 (10th Cir. 2011) (c itations omitted). Defendant contends that the district c ourt erred in applying Colorado’s offer of settlement statute, Colo. Rev. Stat. § 13-17-202(1)(a)(II). Th at statute provides that If the defendant serves an offer of settlement in writing at any time more than fourteen days before the commencement of the trial that is rejected by the plaintiff, and the plaintiff does not rec over a final judgment in excess of the amount offered, then the defendant sh all be awarded actual costs accruing after the offer of settlement to be paid by the plaintiff. . . . Defendant made an offer of se ttlement for $200,000. Plain tiff rejected th at offer. And Plaintiff did not obtain a judgment in ex cess of $200,000. But Plaintiff retained the $250,000 check that Defendant paid to her under a reservation of rights. The district court, reasoning that “the result of the judgment in the case is a net monetary gain for Mrs. Cribari of $50,000 above the offer of settlement,” refused to award Defendant actual costs under the Colorado o ffer of settlement statute. After the parties briefed th eir appeal, but more than four months before oral argument, we issued Stender v. Archstone -Smith Operating Tr., 958 F.3d 938 (10th Cir. 2020). In that opinion, we held that “a valid Federal Rule of Civil Procedure governs over a state procedural rule if th e two rules ‘answer the same question.’” Stender, 958 F.3d at 940 (quoting Shady Grove Orthopedic Assocs., P.A. v. Allstate40 Ins. Co., 559 U.S. 292 (2010)). We specifically held that Rule 54 ’s prevailing party costs provision displaced Colorado’s rule on prevailing party co sts because those provisions “answer the same question.” Id. at 945. Relevant to this issue, there exists a Federal Rule of Civil Procedure that is closely analogous to § 13-17-2 02. Federal Rule of Civil Procedure 68(d) provides: “[i]f the judgment that the of feree finally obtains is no t more favorable than the unaccepted offer, the offeree mu st pay the costs incurred af ter the offer was made.” Fed. R. Civ. P. 68(d). Before we reach the question of whethe r the district court erred in refusing to apply § 13-17-202 because it found Pl aintiff effectively recovered $50,000 more than Defendant offered, we must determine whether Rule 68(d) governs over § 13-17-202—t hus mandating application of the federal rule. Comparing Rule 68(d)’s language with § 13-17-202’s langua ge, we conclude that they answer the same question in this case , where Defendant made the offer of judgment. The state and federal rules are, therefore, in conflict. See Goldberg v. Pac. Indem. Co., 627 F.3d 752, 756 (9th Cir. 2010) (noting that because both Arizona Rule of Civil Procedure 68 and Federal Ru le of Civil Procedur e 68 could apply and result in a different award, the two rules are in conflict (citing Gil de Rebollo v. Miami Heat Assoc., 137 F.3d 56, 66 (1st Cir. 1998)). Because Colorado’s offer of settlement statute and Rule 68(d) answer th e same question in this case, federal law preempts state law and federal law limits Defendant’s witnes s fees. See Stender, 958 F.3d at 945.41 In the posture of this case, then, the district court did err by applying Colorado’s offer of judgment statute and not Federal Rule of Civil Procedure 68(d). But its ultimate conclusion that Defendant could not r ecover its “actual costs” in excess of the $40 per day allo wed under federal law was co rrect. See 28 U.S.C. § 1821(b) (limiting a witness’s attendance f ee to $40 per day). So, we affirm the district court’s costs and fee aw ard, albeit on other grounds. 4
V. For the reasons set forth above, we AFFI RM the district court’s judgment in appeal No. 19-1270, AFFIRM the district court’s judgment in appeal No. 19-1343, and AFFIRM the district court’s judgment in appeal No. 19-1425.

Entered for the Court

Joel M. Carson III Circuit Judge

4 Because Rule 68(d) preem pts application of the st ate rule, we do not reach Defendant’s argument that the district c ourt’s novel interpretation of § 13-17-202 contradicted the statute’s te xt. We further recognize thatno party argued that Rule 68 preempted Colorado’s statute—an issue which arose after the parties completed briefing the issues in this case. And although affirm ing on legal grounds not considered by the trial court is disfavored, any remand instructing the district court to award costs pursuant to the plain language of § 13-17-202 would simply perpetuate error.