PUBLISH

UNITED STATES COURT OF APPEALS

TENTH CIRCUIT 

__________________________________ 

PREDATOR INTERNATIONAL, INC., a 

Colorado corporation,

 Plaintiff,

v.

GAMO OUTDOOR USA, INC., a Florida 

corporation,

 Defendant.

_________________________

JOHN M. COGSWELL,

 Attorney – Appellant.

No. 14-1354

 

APPEAL FROM THE UNITED STATES DISTRICT COURT 

FOR THE DISTRICT OF COLORADO 

(D.C. No. 1:09-CV-00970-PAB-KMT) 

Submitted on the briefs: 

John M. Cogswell, Cogswell Law Offices, P.C., Buena Vista, Colorado, for Attorney – 

Appellant. 

Before HARTZ, GORSUCH, and MORITZ, Circuit Judges. 

FILED 

United States Court of Appeals 

Tenth Circuit 

July 14, 2015

Elisabeth A. Shumaker 

Clerk of Court
2 

HARTZ, Circuit Judge. 

Attorney John Cogswell appeals the imposition of a Rule 11 sanction. Acting on 

behalf of Predator International, Inc., Cogswell filed a lawsuit in April 2009 in the United 

States District Court for the District of Colorado against Gamo Outdoor USA, Inc. and 

Industrias El Gamo, S.A. (collectively, Gamo). The original complaint alleged patent 

infringement and other claims. When it appeared that Lee Phillips, a coinventor of the 

patent at issue, was asserting that he still owned half the patent, Cogswell moved to 

dismiss the infringement claim, explaining that Predator would litigate ownership in state 

court with the expectation of reviving the patent-infringement claim once it had 

established its ownership. The state litigation expanded after Gamo purchased Phillips’s 

interest in the patent. Cogswell then moved in federal court to supplement Predator’s 

complaint with a challenge to Gamo’s claimed interest in the patent and moved to amend 

the complaint by reviving the patent-infringement claim. The district court denied the 

motion. 

Eventually the district court imposed a Rule 11 sanction on Cogswell for filing the 

motion to supplement and amend Predator’s complaint. It justified the sanction on the 

grounds that he was forum shopping on the claims he wished to add, his motion came too 

long after he had learned of Gamo’s purchase of Phillips’s interest in the patent, and 

nothing had changed to justify his reinstating the patent-infringement claim. Cogswell 

appeals the sanction. Exercising jurisdiction under 28 U.S.C. § 1291, we reverse. The 

motion to supplement and amend was not unwarranted under existing law. 
3 

We address our jurisdiction, the requirements for a Rule 11 sanction, and the 

application of these requirements to this case.

I. DISCUSSION 

A. Jurisdiction 

Because this case involves a patent, our jurisdiction could be questioned. For 

actions filed before September 16, 2011, the United States Court of Appeals for the 

Federal Circuit had exclusive jurisdiction over appeals from district-court decisions if the 

lower court’s jurisdiction rested in whole or in part on 28 U.S.C. § 1338(a), which gives 

district courts jurisdiction over civil actions arising under patent legislation. See

28 U.S.C. § 1295(a)(1) (2006).1

 Section 1295(a)(1) might seem to deprive this court of 

jurisdiction because a claim for patent infringement was included in Predator’s original 

complaint, as well as in Predator’s first, second, and third amended complaints, filed 

between May 2009 and March 2010. But at the time of Cogswell’s notice of appeal, the 

most recent complaint was Predator’s fourth amended complaint, filed in September 

2010, which did not contain a patent-infringement claim. And it is that complaint which 

governs our jurisdiction. 

 

1

 As a result of the Leahy-Smith America Invents Act (AIA), Pub. L. No. 112-29, 

§ 19(b), 125 Stat. 284, 331–32 (2011), the Federal Circuit’s jurisdiction has been 

changed. But the AIA applies only to civil actions commenced on or after September 16, 

2011. See AIA § 19(e), 125 Stat. at 333; Wawrzynski v. H.J. Heinz Co., 728 F.3d 1374, 

1378 (Fed. Cir. 2013). 
4 

This conclusion follows from two propositions. First, an amended pleading 

“supersedes the pleading it modifies and remains in effect throughout the action unless it 

subsequently is modified.” Gilles v. United States, 906 F.2d 1386, 1389 (10th Cir. 1990)

(en banc); see Mink v. Suthers, 482 F.3d 1244, 1254 (10th Cir. 2007) (“an amended 

complaint super[s]edes an original complaint and renders the original complaint without 

legal effect” (internal quotation marks omitted)). Second, a court’s subject-matter 

jurisdiction ordinarily is determined by the situation at the time that jurisdiction is 

invoked. This is true of federal district courts. See Grupo Dataflux v. Atlas Global Grp., 

L.P., 541 U.S. 567, 570 (2004) (“the jurisdiction of the court depends upon the state of 

things at the time of the action brought”) (internal quotation marks omitted)); cf. id. at 

572 (noting exception to time-of-filing rule when lack of diversity jurisdiction is cured by 

dismissal of a party); 16 James Wm. Moore et al., Moore’s Federal Practice 

§ 107.41[2][c] (3d. ed. 2011) (“Removability is ordinarily determined as of the date the 

notice of removal is filed.”). And it is also true of a federal appellate court, whose 

jurisdiction is invoked by a notice of appeal. Thus, the Federal Circuit has held that it 

lacked jurisdiction over an appeal because the patent claim originally brought in the 

district court had been voluntarily dismissed without prejudice before entry of final 

judgment and filing of the notice of appeal. See Gronholz v. Sears, Roebuck & Co., 

836 F.2d 515, 518 (Fed. Cir. 1987); see also Holmes Grp., Inc. v. Vornado Air 

Circulation Sys., Inc., 535 U.S. 826, 835 (2002) (Stevens, J., concurring in part and in the 

judgment) (“[I]f the only patent count in a multicount complaint was voluntarily 
5 

dismissed in advance of trial, it would seem . . . clear that the appeal should be taken to 

the appropriate regional court of appeals rather than to the Federal Circuit.”); id. at 840 

(Ginsburg, J., concurring in the judgment) (Because “no patent claim was actually 

adjudicated” in district court, Federal Circuit lacked appellate jurisdiction.). 

Here the notice of appeal was filed after the fourth amended complaint was filed. 

Later events—such as dismissal of a federal claim or mootness—can affect a court’s 

jurisdiction. See Rockwell Int’l Corp. v. United States, 549 U.S. 457, 473‒74 (2007)

(“[W]hen a plaintiff files a complaint in federal court and then voluntarily amends the 

complaint, courts look to the amended complaint to determine jurisdiction.”); Winsness v. 

Yocom, 433 F.3d 727, 736 (10th Cir. 2006) (“Even if we assume that a credible threat of 

prosecution existed before this lawsuit was filed, the prosecutors’ [post-complaint] 

affidavits [disavowing an intention to prosecute] have rendered the controversy moot.”). 

But no such events after the notice of appeal have been presented to us.2

 We have 

jurisdiction under 28 U.S.C. § 1291 and can proceed to the merits. 

 

2

 We note that in response to Predator’s fourth amended complaint, Gamo pleaded a 

counterclaim requesting a declaratory judgment that it had not infringed Predator’s 

patent, and that pleading was operative at the time of the notice of appeal. Such a 

counterclaim might now be sufficient to confer exclusive jurisdiction on the Federal 

Circuit because under the AIA that exclusive jurisdiction now includes “an appeal from a 

final decision of a district court . . . in any civil action arising under, or in any civil action 

in which a party has asserted a compulsory counterclaim arising under, any Act of 

Congress relating to patents . . . .” 28 U.S.C. § 1295(a)(1) (2012) (emphasis added); see 

AIA, § 19(b), 125 Stat. at 331–32. But before the AIA, the Federal Circuit’s jurisdiction 

depended on a claim “arising under” patent legislation. And “a counterclaim . . . cannot 

Continued . . . 
6 

B. The Rule 11 Standard 

Federal Rule of Civil Procedure 11 warns attorneys that by “presenting to the 

court a pleading, written motion, or other paper,” they certify to the best of their 

“knowledge, information, and belief, formed after an inquiry reasonable under the 

circumstances,” that the paper meets the following conditions: 

(1) it is not being presented for any improper purpose, such as to harass, 

cause unnecessary delay, or needlessly increase the cost of litigation; 

(2) the claims, defenses, and other legal contentions are warranted by 

existing law or by a nonfrivolous argument for extending, modifying, or 

reversing existing law or for establishing new law; 

(3) the factual contentions have evidentiary support or, if specifically so 

identified, will likely have evidentiary support after a reasonable 

opportunity for further investigation or discovery; and 

(4) the denials of factual contentions are warranted on the evidence or, if 

specifically so identified, are reasonably based on belief or a lack of 

information. 

Fed. R. Civ. P. 11(b). In short, Rule 11 requires that a “pleading be, to the best of the 

signer’s knowledge, well grounded in fact, warranted by existing law or a good faith 

argument for the extension, modification, or reversal of existing law, and . . . not 

interposed for any improper purpose.” Coffey v. Healthtrust, Inc., 1 F.3d 1101, 1104 

(10th Cir. 1993). “If, after notice and a reasonable opportunity to respond, the court 

determines that Rule 11(b) has been violated, the court may impose an appropriate 

 

serve as the basis for ‘arising under’ jurisdiction.” Vornado, 535 U.S. at 831. Gamo’s 

patent-related counterclaim does not defeat our jurisdiction.
7 

sanction,” meaning one “limited to what suffices to deter repetition of the conduct or 

comparable conduct by others similarly situated.” Fed. R. Civ. P. 11(c)(1), (4). 

The district court imposed a Rule 11 sanction against Cogswell, Predator’s 

attorney, for filing a motion to supplement its complaint with a challenge to Gamo’s 

claimed interest in the patent and to amend its complaint by reviving the patentinfringement claim. Because the court found “no evidence that Predator acted with 

malice or bad faith,” Predator Int’l, Inc. v. Gamo Outdoor USA, Inc., 

No. 09-cv-00970-PAB-KMT, 2014 WL 201662, at *8 (D. Colo. Jan. 17, 2014), the 

question before us is whether the motion to supplement and amend the complaint was 

unwarranted under the facts or law. To answer that question, the district court must 

evaluate Cogswell’s conduct under a standard of “objective reasonableness—whether a 

reasonable attorney admitted to practice before the district court would file such a 

document.” Adamson v. Bowen, 855 F.2d 668, 673 (10th Cir. 1988). Because our 

adversary system expects lawyers to zealously represent their clients, this standard is a 

tough one to satisfy; an attorney can be rather aggressive and still be reasonable. Even if 

a legal position in a pleading is clearly contrary to current law, it is not sanctionable if the 

position is warranted “by a nonfrivolous argument for extending, modifying, or reversing 

existing law or for establishing new law.” Fed. R. Civ. P. 11(b)(2). This standard can be 

compared to the lesser standard for sanctions under Rule 37(a)(5)(A) (for improperly 

opposing discovery disclosure), which ordinarily must be imposed to compensate the 

opposing party for its expenses unless the objection to disclosure “was substantially 
8 

justified.” And even if counsel obnoxiously tries a court’s patience with unfounded or 

silly arguments, the sanction must be based solely on those violations of Rule 11, not on 

other rejected arguments that were in fact objectively warranted. 

On appeal we “apply an abuse-of-discretion standard in reviewing all aspects of a 

district court’s Rule 11 determination. A district court would necessarily abuse its 

discretion if it based its ruling on an erroneous view of the law or on a clearly erroneous 

assessment of the evidence.” Cooter & Gell v. Hartmarx Corp., 496 U.S. 384, 405 

(1990). To evaluate the district court’s imposition of the sanction against Cogswell, we 

set forth the chronology of relevant events, noting the applicable law as appropriate. 

C. Application to This Case 

In January 2000, air-gun enthusiasts Tom May and Lee Phillips filed a provisional 

patent application for a new type of air-gun pellet they had invented. A few months later, 

Predator was formed to manufacture, promote, and sell the new pellet, with May as 

President and Phillips as Vice President and Secretary. But Phillips was involved in an 

automobile accident that led to a lengthy prison term, and he resigned from Predator in 

early 2002, selling May “all of [his] capital stock and rights and interests in Predator 

International, Inc.” Aplt. App. at 78. The patent application was granted in 2003. On 

January 1, 2007, the current owners of Predator bought May’s interest in the company. 

About two years later, Predator discovered that Gamo was marketing an air-gun 

pellet substantially identical to its own pellet, using virtually the same trade dress, slogan, 

and advertising copy, which had allegedly caused customer confusion and damaged 
9 

Predator’s reputation. May assigned his interest in the patent to Predator, and in April 

2009, Cogswell filed on behalf of Predator a federal complaint against Gamo asserting 

claims for trade-dress infringement, slogan infringement, copyright infringement, 

violation of Colorado’s Consumer Protection Act, unjust enrichment, unfair competition, 

and patent infringement. 

In February 2010 Predator attempted to obtain from Phillips a written assignment 

of his patent-ownership rights. Phillips refused and claimed a 50% ownership interest in 

the patent. His claim of ownership presented a problem for Predator’s patentinfringement claim because a co-owner of a patent does not have standing to sue for 

infringement unless all other co-owners join the suit. See Israel Bio-Eng’g Project v. 

Amgen, Inc., 475 F.3d 1256, 1264–65 (Fed. Cir. 2007). The problem did not, however, 

require dismissal of Predator’s patent-infringement claim. See Kunkel v. Topmaster Int’l, 

Inc., 906 F.2d 693, 695 (Fed. Cir. 1990) (“merely because a question of contract law 

must be decided prior to reaching the infringement question does not defeat federal 

subject matter jurisdiction” (internal quotation marks omitted)). Although the 

infringement claim could not be decided before the ownership issue was resolved, the 

federal court could assume supplemental jurisdiction over the patent-ownership claim, 

see 28 U.S.C. § 1367(a) (district courts have supplemental jurisdiction “over all other 

claims that are so related to claims in the action within [the court’s] original jurisdiction 

that they form part of the same case or controversy”); Energy Recovery, Inc. v. Hauge, 

133 F. Supp. 2d 814, 820 (E.D. Va. 2000) (“precisely because patent ownership 
10 

represents a necessary predicate issue, it is sufficiently related to Plaintiff’s patent noninfringement claim to afford Plaintiff a basis for supplemental jurisdiction”); cf. Kunkel, 

906 F.2d at 697 n.1 (under former version of 28 U.S.C. § 1367, district court in patent 

case would have pendent jurisdiction over claim of breach of patent-license contract). Or 

the infringement proceedings could be stayed while ownership was litigated in state 

court. See Loral Fairchild Corp. v. Matsushita Elec. Indus. Co., 840 F. Supp. 211, 

215‒18 (E.D.N.Y. 1994) (supplemental jurisdiction exercised over patent-ownership 

claims in patent-infringement suit, but case stayed pending outcome in state court). 

But Predator took another course. On March 4, 2010, it moved to dismiss without 

prejudice its patent-infringement claim, stating its intent to prove its exclusive ownership 

in state court and then refile the claim in the federal lawsuit. Its motion to dismiss 

explained: 

Predator vehemently disagrees that Mr. Phillips has any [patent] rights . . . 

and that he is, in fact, obligated to provide Predator with a written 

assignment evidencing that ownership. Nonetheless, in recognition of the 

fact that standing is a threshold issue in every action, Predator recognizes 

that it must resolve this ownership dispute with Mr. Phillips, obtain a 

formal patent assignment from him, or re-file with Mr. Phillips as a coplaintiff, to cure the potential defect in standing. Rather than bring 

Mr. Phillips into this case and plead ancillary state law claims regarding 

ownership, resulting in a time-consuming and complicated sideshow over 

only one of multiple claims made in this case, Predator plans to proceed 

with litigation in Colorado state court against Mr. Phillips. Predator 

certainly hopes that this ownership dispute can be resolved swiftly so that it 

may re-file its patent infringement claim as soon as possible. 

Predator, 2014 WL 201662, at *1 (internal quotation marks omitted) (emphasis added). 
11 

In May, while its motion to dismiss was still pending, Predator moved to file a 

fourth amended complaint excluding the patent-infringement claim. On September 9 the 

federal district court granted the motion, and it later denied as moot Predator’s motion to 

dismiss its infringement claim. 

The May motion to amend stated that “Predator seeks to voluntarily dismiss its 

patent infringement claims . . . because it has discovered that it cannot prove that it had 

standing to pursue these claims without a written assignment from Mr. Lee Phillips.” Id. 

at *2 (emphasis added) (internal quotation marks omitted). Both Gamo and the district 

court interpreted this statement as a concession that Predator lacked standing to bring the 

claim. See id. at *4, *5. But Predator has always insisted that it owned the patent. It was 

simply acknowledging that its ownership of the patent had to be litigated and expressing 

its view that the best forum for that litigation would be the state court. That is quite 

different from an admission that it lacked standing. Indeed, at the outset of a case it is 

enough to allege the facts (here, ownership of the patent) establishing standing. If the 

allegations are, as here, challenged, then the facts have to be litigated; but they can be 

litigated in the forum where jurisdiction is at issue. The Supreme Court has taught: 

“[E]ach element [of standing] must be supported in the same way as any other matter on 

which the plaintiff bears the burden of proof, i.e., with the manner and degree of evidence 

required at the successive stages of litigation.” Lujan v. Defenders of Wildlife, 504 U.S. 

555, 561 (1992). General allegations suffice at the pleading stage, although affidavits 

may be necessary on a summary-judgment motion and ultimately a trial may be 
12 

necessary to resolve the issue. See id. Predator acknowledged that a trial would be 

necessary but wanted that trial to be in state court. As Predator later stated in its response 

to Gamo’s motion for sanctions: 

Predator has never conceded that it did not have standing. It has only 

conceded that, in light of GAMO’s objection to Predator’s full ownership 

of the patent, a hearing or trial on standing would be required and Predator 

believed it would be more sensible to deal with it in state court than in this 

Court. . . . 

Predator, 2014 WL 201662, at *5 (brackets and internal quotation marks omitted). 

There has been no contention that Predator’s claim of ownership was frivolous. 

According to Predator’s pleadings, not only had Phillips sold to May “all of [his] capital 

stock and rights and interests in Predator International, Inc.,” Aplt. App. at 78, but 

Phillips had never requested or received royalties, objected to Predator’s holding itself 

out as the sole owner of the patent, or attempted to make use of the patent. Predator 

further alleged that the patent had always been treated as an asset on its books, that May 

believed (and Predator’s investors and subsequent owners relied on that belief) that 

Phillips had no remaining patent-ownership interest, and that in 2003 Phillips had 

confirmed to May that he had no interest in the patent. 

Meanwhile, in April 2010 Predator had filed suit against Phillips in Colorado state 

court. Its complaint sought a determination that Phillips had transferred or must transfer 

his interest in the patent to May (and consequently to Predator). It presented six legal 

theories supporting that relief: (1) breach of contract, (2) breach of the implied duty of 

good faith and fair dealing, (3) contract reformation, (4) breach of implied contract, 
13 

(5) breach of implied exclusive license, and (6) breach of fiduciary duty, all centered on 

the same allegations of Phillips’s refusal to acknowledge Predator as the exclusive owner 

of the patent. 

In June, Phillips assigned his purported interest in the patent to Gamo. Predator 

learned about the assignment no later than September 27, and on November 2 it filed in 

state court an amended complaint adding new claims against Phillips that his assignment 

to Gamo breached his duties to Predator and that Predator still owned the patent. Soon 

after, Gamo moved to intervene in the state-court suit, and the suit expanded further. 

Alleging that he had never relinquished his rights to Predator or the patent, Phillips filed 

on November 15 eight counterclaims against Predator, asserting that (1) Predator had 

breached its fiduciary duty to him as a 50% stockholder; Predator had (2) stolen and 

(3) converted his rights in the company; (4) Predator had been unjustly enriched at his 

expense; (5) Predator owed him an accounting; and (6–8) Phillips’s sale and assignment 

to May was void and Phillips retained a 50% ownership interest in Predator. The next 

day Phillips filed a third-party complaint against Tom May. He asserted claims for 

(1) breach of fiduciary duty, (2) civil theft, (3) conversion, (4) unjust enrichment, 

(5) fraudulent misrepresentation, (6) constructive fraud, and (7) an accounting; and he 

sought a declaratory judgment that (8) Phillips’s assignment to May was void, (9) Phillips 

owned 50% of Predator, (10) May’s sale of Predator to its current owners was void, and 

(11) Phillips retained a 50% interest in the patent. Also on that day Gamo submitted a 

proposed answer and six counterclaims against Predator (subject to Gamo’s being 
14 

permitted to intervene). The counterclaims sought damages for (1) fraudulent 

misrepresentation and (2) fraudulent concealment, based on Predator’s allegedly false 

allegations in its original federal-court complaint that it had full ownership of the patent 

(and therefore standing to claim infringement), which induced Gamo to expend resources 

defending against those allegations. The counterclaims further requested a declaratory 

judgment that (3) Phillips’s sale of his patent interest to Gamo was valid, (4–5) Gamo 

now owned 50% of the patent, and (6) Predator lacked standing to pursue a patentinfringement claim in federal court. 

In December Predator moved for a separate trial on patent ownership. On 

January 1, 2011 (yes, the state court worked that day) the court granted Gamo’s motion to 

intervene and denied the motion for separate trials. Later in January, Predator filed 

motions to dismiss Gamo’s counterclaims (except for patent ownership) on the grounds 

of standing and state-federal comity and to dismiss Phillips’s counterclaims on the 

grounds that Phillips’s sale and assignment to May was valid and that his claims were 

barred by the statute of limitations or laches. On April 1 the state court denied the 

motions, save for dismissing Gamo’s counterclaim that Predator lacked standing in 

federal court. It also awarded Gamo some attorney fees because Predator’s motion to 

dismiss two of the counterclaims failed to cite any legal authority. 

Three months later, on July 11, 2011, Predator filed in federal court the motion 

that is the source of the Rule 11 sanction. It moved (1) for leave to file a supplemental 
15 

complaint asserting, among other things, a patent-ownership claim against Gamo,3 and 

(2) for leave to amend its complaint to reassert its patent-infringement claim, although 

requesting a stay of the trial of the infringement claim until Predator first proved its full 

ownership of the patent.

Neither request was unwarranted under the facts or the law. The rule governing 

motions to supplement states that “the court may, on just terms, permit a party to serve a 

supplemental pleading setting out any transaction, occurrence, or event that happened 

after the date of the pleading to be supplemented.” Fed. R. Civ. P. 15(d). Leave to 

supplement a complaint with “post-complaint transactions, occurrences or events . . . 

should be liberally granted unless good reason exists for denying leave, such as prejudice 

to the defendants.” Walker v. United Parcel Serv., Inc., 240 F.3d 1268, 1278 (10th Cir. 

2001) (internal quotation marks omitted). Similarly, for motions to amend, “[t]he court 

should freely give leave when justice so requires.” Fed. R. Civ. P. 15(a)(2); see Minter v. 

Prime Equip. Co., 451 F.3d 1196, 1208 (10th Cir. 2006) (“in general permission is 

liberally granted where there is no prejudice” (internal quotation marks omitted)); Hardin 

v. Manitowoc-Forsythe Corp., 691 F.2d 449, 456 (10th Cir. 1982) (“Rule 15 was 

promulgated to provide the maximum opportunity for each claim to be decided on its 

merits rather than on procedural niceties.”). 

 

3

 The motion to supplement included claims in addition to the patent-ownership claim 

against Gamo. But we ignore these claims because the sanction imposed by the district 

court was not based on Predator’s filing them. 
16 

On its face, Predator’s motion to supplement conformed to Rule 15(d). Predator 

had no ownership dispute with Gamo until Gamo acquired Phillips’s interest in the 

patent. The magistrate judge noted that it was undisputed that the supplemental claim 

was “premised on ‘transactions, occurrences, or events that happened after the date of the 

pleading to be supplemented.’” Predator Int’l, Inc. v. Gamo Outdoor USA, Inc., 

No. 09-cv-00970-PAB-KMT, 2011 WL 7627422, at *5 (D. Colo. Sept. 19, 2011) 

(quoting Fed. R. Civ. P. 15(d) (brackets omitted)). Predator could have brought the 

patent-ownership claim in a separate action and then moved to consolidate the actions. 

Supplementation under Rule 15(d) is simply a more efficient vehicle to accomplish that 

objective. See Arp v. United States, 244 F.2d 571, 574 (10th Cir. 1957) (“Had the court 

refused permission to file [the supplemental complaint], the Government could have 

proceeded by an original complaint in an independent action, and the identical issues 

would have been presented and determined. We find no abuse of discretion by the trial 

court [in allowing supplementation under Rule 15(d) instead].”); see also 6A Charles A. 

Wright et al., Federal Practice and Procedure § 1506 (3d ed. 2010) (“[T]he usual effect of 

denying leave to file a supplemental pleading because it states a new cause of action is to 

force [the] plaintiff to institute another action and move for consolidation under Rule 

42(a) in order to litigate both claims in the same suit, a wasteful and inefficient result.” 

(footnote and internal quotation marks omitted)). (In response to Gamo’s motion for 

sanctions, Predator argued: “By proposing [the patent-ownership claim] under 

Fed.R.Civ.P. . . . 15(d) . . . , Predator was seeking permission, in the discretion of the 
17 

Court, to have these claims heard in this case and not in a separate proceeding in 

furtherance of the policy of conservation of judicial resources.” Aplt. App. at 167.) 

Likewise, Predator’s request to amend the complaint by reinstating the patentinfringement claim was proper on its face. It was accompanied by a request to stay 

proceedings on the claim until resolution of Predator’s claim that it had sole ownership of 

the patent. Thus, the burden on the federal court was essentially the same as that 

anticipated when Predator was permitted to delete the infringement claim from its 

complaint on the understanding that it intended to refile and pursue the claim once 

ownership of the patent was resolved. And there was no problem in reasserting the claim 

without conclusive evidence of standing. As previously noted, Predator did not concede 

a lack of standing. It alleged the factual basis for standing and conceded only that 

standing would have to be proved. That is sufficient for the pleading stage. See Lujan, 

504 U.S. at 561.

Nevertheless, the motions to supplement and amend could be denied if there was 

good reason for denial. And if the grounds for denial were so strong and obvious that the 

motions were unwarranted, then the Rule 11 sanction was proper. In our view, however, 

the district court stated inadequate reasons for deciding that the motions were 

unwarranted. 

The district court gave three reasons for the sanction. First, the court held that 

Predator’s motion was sanctionable “forum shopping.” Predator, 2014 WL 201662, at 

*6; see id. at *5–6. Second, the court held that there was no justification for delaying the 
18 

motion until July 2011, long after the deadline for amending pleadings and at least ten 

months after Predator learned of Phillips’s assignment to Gamo of his interest in the 

patent. See id. at *5. Third, the court noted that Predator had no better ground for 

asserting standing than it had when it dismissed the patent-infringement claim. Although 

acknowledging Predator’s argument that “it never conceded its lack of standing, only its 

lack of evidence of standing,” the court viewed this as “a distinction without a 

difference.” Id. And seizing on Predator’s statement in its response to the motion for 

sanctions that “Predator, . . . concerned that [Phillips’s] Sale and Assignment [to May of 

his interest in Predator] was not by itself sufficient to show standing, [had been] 

compelled by professional prudence [in the spring of 2010] to dismiss its patent 

infringement claim without prejudice,” Aplt. App. at 148, the court said that “[t]o reassert 

an identical claim without having obtained additional evidence of standing was therefore, 

by Predator’s own assessment, imprudent,” Predator, 2014 WL 201662, at *5. We 

discuss each of these three grounds. 

1. Forum Shopping 

The first reason given by the district court for sanctioning Cogswell was that 

Predator’s motion was illegitimate forum shopping. It said: 

Forum shopping may constitute an improper purpose under Rule 11 where 

a party attempts to avail itself of a forum it perceives to be more favorable 

without any legal or factual basis for doing so, thereby causing unnecessary 

delay, or needlessly increasing the cost of litigation. See Bolivar v. 

Pocklington, 975 F.2d 28, 32 (1st Cir. 1992); Fransen v. Terps Ltd. 

Liability Co., 153 F.R.D. 655, 660 (D. Colo. 1994); Cusano v. Klein, 2007 

WL 2825730, at *4 (C.D. Cal. Jan. 29, 2007). 
19 

Id. at *4 (brackets and internal quotation marks omitted). 

There was no forum shopping with respect to the infringement claim, which had 

not been (and could not have been) brought in state court, see 28 U.S.C. § 1338(a) (state 

courts do not have jurisdiction over patent-infringement claims), contrary to the district 

court’s erroneous statement that Predator had “voluntarily dismiss[ed] that claim and 

refil[ed] it in state court,” Predator, 2014 WL 201662, at *1 (citation omitted). But even 

with respect to the patent-ownership claim, the court misconceived the pertinent legal 

doctrine on forum shopping. “Forum shopping is not an improper purpose [under Rule 

11] if a ground for federal jurisdiction arguably exists.” 2 James Wm. Moore et al., 

supra, at § 11.11[8][b]. There is no impropriety simply in pursuing the same claim 

simultaneously in state and federal courts. The general rule is that “both the state court 

and the federal court, having concurrent jurisdiction, may proceed with the litigation at 

least until judgment is obtained in one of them which may be set up as res judicata in the 

other,” Donovan v. City of Dallas, 377 U.S. 408, 412 (1964) (internal quotation marks 

omitted), and even then, it is ordinarily the latter court that must decide the question of 

res judicata, see id. The district court distinguished Donovan because the holding in that 

case was that the state court could not enjoin a federal lawsuit raising a claim similar to 

one disposed of in the state court. But the Supreme Court’s dictum in Donovan is clear 

and states well-settled law. See United States v. Lot 85, Cnty. Ridge, 100 F.3d 740, 742 

(10th Cir. 1996); Aluminum Prods. Distribs., Inc. v. Aaacon Auto Transp., Inc., 549 F.2d 
20 

1381, 1383–84 (10th Cir. 1977); see also Colo. River Water Conservation Dist. v. United 

States, 424 U.S. 800, 817 (1976) (“Generally, as between state and federal courts, the rule 

is that the pendency of an action in the state court is no bar to proceedings concerning the 

same matter in the Federal court having jurisdiction.” (internal quotation marks omitted)). 

The three opinions cited by the district court in support of its above-quoted 

statement on forum shopping do not support the sanction here. In Bolivar, 975 F.2d at 

31–32, a Rule 11 sanction was imposed on the sole shareholder of certain corporations

who, after dismissal of claims against the defendant by the corporations, brought the 

same claim in his own name against the same defendant before another judge (of the 

same court). The claims clearly belonged to the corporations, not the shareholder. Here, 

the claims to be added by Predator’s motion were legally sound. In Fransen, 153 F.R.D. 

at 659–60, the court imposed Rule 11 sanctions because the plaintiff filed a suit that was 

clearly meritless because of the res judicata effect of a prior state-court judgment. Here, 

there was no state-court judgment when Predator filed its motion. And in Cusano, 2007 

WL 2825730, at *4, the district court simply ordered an attorney to show cause why he 

should not be sanctioned for filing a frivolous motion to recuse the judge. In each of the 

three cases the sanctioned attorney was trying to proceed before another court or another 

judge of the same court. The basis of the sanction, however, was not forum shopping 

simpliciter but, rather, filing a pleading that was patently unfounded. There has been no 

such challenge to the legal or factual basis of Plaintiff’s additional claims, nor to the 

district court’s jurisdiction to hear them. 
21 

This is not to say that a federal court must always permit amendment of a 

complaint to add a claim already pending in state court. The Supreme Court has 

recognized several abstention doctrines, under which a federal court should not hear a 

case when the same claims are before a state court. But the district court did not mention 

any of these doctrines, and we would be loath to affirm a Rule 11 sanction because of a 

legal doctrine that was not invoked by the court that imposed the sanction. We suspect 

that a district court would not think it appropriate to say in that circumstance that any 

“reasonable attorney admitted to practice before the district court,” Adamson, 855 F.2d at 

673, would have known of the doctrine precluding the pleading filed by the attorney. 

Moreover, we cannot say that any abstention doctrine made Cogswell’s action 

unreasonable. Some certainly would not justify abstention here. And to the extent that 

others could justify abstention, they are discretionary, and their application by the district 

court was not so predictable in this case that to pursue the motion to supplement and 

amend was legally unwarranted. 

The three more traditional abstention doctrines—which apply to cases (1) 

“presenting a federal constitutional issue which might be mooted or presented in a 

different posture by a state court determination of pertinent state law,” Colorado River, 

424 U.S. at 814 (internal quotation marks omitted); (2) “where there have been presented 

difficult questions of state law bearing on policy problems of substantial public import 

whose importance transcends the result in the case then at bar,” id.; or (3) where “federal 

jurisdiction has been invoked for the purpose of restraining state criminal 
22 

proceedings, . . . state nuisance proceedings[,] . . . or collection of state taxes,” id. at 816, 

817—are irrelevant here. 

More relevant is the Colorado River doctrine, although it is “considerably more 

limited,” id. at 818, than the previously mentioned “extraordinary and narrow” traditional 

abstention doctrines, id. at 813. Under the Colorado River doctrine, “reasons of wise 

judicial administration” may require dismissal in favor of concurrent state proceedings. 

Id. at 818. As the Supreme Court later explained, Colorado River recognized four factors 

to consider when deciding whether to abstain from exercising jurisdiction: (1) in an in 

rem action, whether the federal court was the first to assume jurisdiction over the 

property; (2) “the inconvenience of the federal forum”; (3) “the desirability of avoiding 

piecemeal litigation”; and (4) “the order in which jurisdiction was obtained by the 

concurrent forums.” Moses H. Cone Mem’l Hosp. v. Mercury Constr. Corp., 460 U.S. 1, 

15 (1983). These four factors do not support abstention here: this is not an in rem action, 

the federal forum was not inconvenient, exclusive federal jurisdiction over patentinfringement claims would necessarily result in some degree of piecemeal litigation, and 

the federal forum had jurisdiction first. Moses H. Cone, however, identified other factors 

that may be more applicable, “such as the vexatious or reactive nature of either the 

federal or the state action . . . ; whether federal law provides the rule of decision . . . ; and 

the adequacy of the state court action to protect the federal plaintiff’s rights . . . .” Fox v. 

Maulding, 16 F.3d 1079, 1082 (10th Cir. 1994) (citing Moses H. Cone, 460 U.S. at 18 

n.20, 23, 28). And “[o]ther courts also have considered whether the party opposing 
23 

abstention has engaged in impermissible forum-shopping.” Id. Even so, “[n]o single 

factor is dispositive” and “[o]nly the clearest of justifications will warrant dismissal.” Id.

(internal quotation marks omitted); see FDIC v. Nichols, 885 F.2d 633, 637 (9th Cir. 

1989) (“We are aware of no doctrine of abstention or deference of jurisdiction which 

authorizes federal courts to decline to exercise jurisdiction on [forum-shopping] 

ground[s] alone.”).

Also relevant is the discretion of the district court to refuse to exercise jurisdiction 

over a declaratory-judgment claim. See Wilton v. Seven Falls Co., 515 U.S. 277, 286‒87 

(1995) (noting that the Declaratory Judgment Act, 28 U.S.C. § 2201(a), “provides that a 

court ‘may declare the rights and other legal relations of any interested party seeking such 

declaration’”). District courts should consider five factors: 

[1] whether a declaratory action would settle the controversy; [2] whether it 

would serve a useful purpose in clarifying the legal relations at issue; 

[3] whether the declaratory remedy is being used merely for the purpose of 

procedural fencing or to provide an arena for a race to res judicata;

[4] whether use of a declaratory action would increase friction between our 

federal and state courts and improperly encroach upon state jurisdiction; 

and [5] whether there is an alternative remedy which is better or more 

effective. 

Mid-Continent Cas. Co. v. Vill. at Deer Creek Homeowners Ass’n, 685 F.3d 977, 980–81 

(10th Cir. 2012) (internal quotation marks omitted). Ultimately, however, the issue for 

the court to decide is simply “whether the controversy can better be settled in a pending 

action.” ARW Exploration Corp. v. Aguirre, 947 F.2d 450, 454 (10th Cir. 1991). This is 

a “practical” decision, St. Paul Fire & Marine Ins. Co. v. Runyan, 53 F.3d 1167, 1170 
24 

(10th Cir. 1995), which may turn on any number of nuances, making anticipation of a 

district court’s decision difficult, if not impossible, to predict. 

 Under these authorities, Predator’s effort to pursue its patent-ownership claim in 

federal court was, if not guaranteed to be successful, at least objectively reasonable. It 

would not have been clear to a reasonable attorney that denial of the motion to amend 

was demanded by settled law. Consider the full context. When Predator originally sued 

Phillips in state court, it was suing a defendant who was not a party in the federal 

proceedings and the subject matter of the suit—patent ownership—was distinct from the 

issues raised in the federal litigation, with no significant overlapping law or facts. But 

after Gamo bought Phillips’s interest in the patent, various counterclaims were filed in 

state court that significantly expanded the issues. Predator moved to dismiss the new 

counterclaims and sought to have the patent-ownership claim tried separately. The state 

court rejected Predator’s requests (except for dismissing one counterclaim), thereby 

reducing the efficiency in having the state court, rather than the federal court, decide the 

ownership claim. Three months later, Predator moved to amend its federal complaint to 

add an ownership claim to its other claims against Gamo. At that time the state court had 

issued no rulings on the ownership claim—neither party had sought any—and little

discovery had been conducted. Moreover, bringing the ownership claim in federal court 

had several advantages: it avoided delays in the federal infringement claim that could 

result from appeals in state court of any decision regarding patent ownership; it 

consolidated claims against a party already before the federal court; and it avoided 
25 

piecemeal litigation (even if Predator proved its patent ownership in state court, it would 

still need to file an infringement action in federal court because of exclusive federal 

jurisdiction over patent claims under 28 U.S.C. § 1338). Predator adverted to these 

considerations when it gave the district court the following reasons for filing its motion to 

supplement and amend its complaint: 

to accelerate final judgment on the standing issue, to mitigate GAMO’s 

splitting of claims between this Court and state court, to provide a hedge 

against the error-ridden proceeding in state court which had the appearance 

of an interminable controversy replete with appeals, remands and retrials, 

and to permit this Court to determine standing which would have been the 

case if GAMO, pursuant to its duty of candor and Fed.R.Civ.P. 26, had 

disclosed to this Court and Predator in June 2010 that it had acquired 

Phillips’ interests, if any, in the patent. 

Predator, 2014 WL 201662, at *5 (internal quotation marks omitted). If in those 

circumstances it was “unwarranted” for Predator to seek to pursue its ownership claim in 

federal court, then it is hard to see how it could ever be proper to pursue in federal court a 

state-law claim already pending in state court. 

 It is no answer to say that Predator was unhappy with rulings by the state court,4

because we would presume that parties seeking federal-court review anticipate there 

being an advantage to doing so. In any event, the state court had not issued any rulings 

 

4

 After listing Predator’s state-court defeats, see Predator, 2014 WL 201662, at *2, the 

district court referred to those “adverse rulings” as motivating Predator’s filing of the 

motion to amend and supplement, id. at *5, *6, without differentiating between those 

rulings that occurred before the filing of the motion (the denial of the motions for 

separate trials and to dismiss Phillips’s and Gamo’s counterclaims) and those that 

occurred after it was filed (the denial of a motion to recuse the judge and the granting of a 

motion to disqualify Cogswell). 
26 

related to the merits of the claim Predator sought to pursue in federal court. The only 

substantive rulings in state court before Predator filed its motion to supplement and 

amend its complaint were the rulings that defeated the efficiencies of pursuing the 

ownership claim in state court: the ones that made clear that the state-court action was 

going to be significantly expanded and the patent-ownership claim would be tried with all 

the other claims. (The sole other ruling was an award of $2,481.50 in attorney fees for 

Predator’s unsupported motion to dismiss two of Gamo’s counterclaims.) It was only on 

July 15, 2011, four days after the motion to supplement and amend was filed, that Gamo 

and Phillips renewed a motion to disqualify Cogswell (two earlier attempts had been 

unsuccessful), which was not granted until November 29, 2011.

In holding that Predator’s motion to supplement and amend its complaint was not 

unwarranted, we find support in a federal district-court decision on a similar matter in a 

similar case. In Energy Recovery, 133 F. Supp. 2d at 815‒16, the parties disputed 

whether the defendant had transferred to the plaintiff his rights to a patent. The plaintiff 

initially sued the defendant in state court for tortious business interference, 

misappropriation of trade secrets, detinue, and common-law and statutory conspiracy. 

See id. at 816. The plaintiff then filed suit in federal court against the defendant, bringing 

Lanham Act claims for unfair competition and cyber piracy and a request for a 

declaration of patent noninfringement. See id. The defendant requested the federal court 

to stay the noninfringement action because the ownership issue—a matter of state law—

would be resolved in the state litigation. The district court decided not to stay the action. 
27 

First, the proceedings on the plaintiff’s other federal claims (like Predator’s) would 

continue anyway. Second, the state court lacked jurisdiction over patent-infringement 

claims, so it could not address all issues presented in the declaratory-judgment claim. 

And third, prompt resolution of the patent-ownership issue in state court was not 

guaranteed, and the lack of progress on the issue in state court meant that proceeding in 

federal court would not interfere excessively with the state proceedings. All in all, the 

court thought that proceeding with the claim would serve judicial economy. See id. at 

822‒23. 

To recapitulate, Predator had not forum-shopped its patent-infringment claim 

because, contrary to the district court’s understanding, it had not filed (and could not file) 

the claim in state court. And as for the patent-ownership claim, the legal proposition 

relied on by the district court—that a party engages in improper forum shopping if it 

“attempts to avail itself of a forum it perceives to be more favorable without any legal or 

factual basis for doing so,” Predator, 2014 WL 201662, at *4 (emphasis added)—does 

not apply because there was a legal and factual basis for pursuing the claim in federal 

court even though it was already before the state court. Although there are legal 

doctrines under which the district court could have abstained from considering the 

ownership claim, the district court did not set forth the doctrines in its order; a fortiori, 

the court made no finding that a reasonable attorney would have known that the motion 

to amend would be precluded by one of those doctrines; and, in any event, none of those 

doctrines clearly precluded the proposed amendment. As a result of its legal error, the 
28 

district court abused its discretion in relying on forum shopping as a ground for imposing 

the Rule 11 sanction. 

On this ground alone, we must reverse the award of sanctions and remand for 

further proceedings. When a court bases its exercise of discretion on the confluence of 

several factors and it was improper for the court to rely on one of those factors, we must 

reverse “unless we can say as a matter of law that it would have been an abuse of 

discretion for the trial court to rule otherwise.” Ashby v. McKenna, 331 F.3d 1148, 1151 

(10th Cir. 2003) (internal quotation marks omitted). That standard for affirmance is not 

satisfied here. The district court’s other two grounds for imposing sanctions are not 

compelling, and at the least do not mandate the full sanction imposed. We briefly discuss 

each ground. 

2. Delay 

To support the sanctions imposed on Cogswell, the district court relied in part on 

the delay between when Predator learned of Gamo’s acquisition of Phillips’s patentownership rights and when it moved to supplement and amend its complaint in federal 

court, see Predator, 2014 WL 201662, at *5, particularly in light of the pretrial order’s 

deadline for amending pleadings, which had expired nearly two years earlier. 

The deadline in the pretrial order, however, was the final date to “amend” 

pleadings. Id. at *3. And even if read to encompass motions to supplement the 

complaint, but see Ohio Valley Envtl. Coal. v. U.S. Army Corps of Eng’rs, 243 F.R.D. 

253, 256 (S.D. W. Va. 2007) (deadline for amending pleadings did not apply to 
29 

supplemental pleadings), it could not preclude Predator from filing a separate suit on the 

ownership claim against Gamo, and then seeking consolidation of the two suits. The 

district court could decide that the supplemental claim should proceed as a separate case; 

but there was nothing unwarranted in giving the district court the choice of whether to 

consolidate the claims with those that were pending. See Wright et al., supra, § 1506 

(“[T]he usual effect of denying leave to file a supplemental pleading because it states a 

new cause of action is to force [the] plaintiff to institute another action and move for 

consolidation under Rule 42(a) in order to litigate both claims in the same suit, a wasteful 

and inefficient result.” (footnote and internal quotation marks omitted)). 

As for the motion to amend to add the patent-infringement claim, it was 

objectively reasonable for Predator to think that the amendment did nothing more than 

follow up on what everyone had anticipated when the infringement claim was dropped 

from Predator’s complaint. Indeed, when Gamo had argued that Predator’s dismissal of 

its infringement claim should be conditioned on reimbursement of the expenses it had 

incurred in defending the claim, the magistrate judge “agree[d] with Predator that much 

of the work and discovery related to Predator’s patent infringement claim is . . . 

applicable . . . to a later-filed patent infringement action, should Predator choose to 

pursue it.” Predator Int’l, Inc. v. Gamo Outdoor USA, Inc., No. 09-cv-00970-PABKMT, 2010 WL 3630118, at *8 (D. Colo. Sept. 9, 2010). If anything, the amendment 

was premature, not late, because ownership of the patent had not yet been resolved. In 
30 

these circumstances, it was not objectively unreasonable for Predator to pursue the 

motion to supplement and amend despite the pretrial order’s deadline.

Turning to the nine-month delay between when Predator learned that Gamo had 

acquired Phillips’s interest in the patent and when Predator moved to add its claims in 

federal court, Predator reasonably argued that the important date was not when Gamo 

acquired Phillips’s interest, or even when Predator learned of the acquisition, but rather 

when it became clear that the state-court litigation would not be a focused dispute 

between Predator and Phillips regarding who owned the patent. It was not clear that the 

state case had significantly expanded until (1) Gamo and Phillips sought to add numerous 

claims in the state case, (2) the state court denied Predator’s motion to try the ownership 

issue separately, and (3) the state court, over Predator’s objections, approved the 

expansion of the case. Moreover, since it then became clear that Predator’s rival in the 

state case would be Gamo, which was already the opposing party in the federal case, 

there was less efficiency in segregating the ownership claim from those already in federal 

court. 

The district court acknowledged Predator’s arguments regarding why it now made 

sense to litigate ownership in federal court, but it did not address the contention that the 

nature of the state litigation had significantly changed in April 2011, when the state court 

confirmed that Gamo’s claims could be litigated in that forum. Rather, it relied on 

“Predator’s assertion that, had it known of the assignment earlier, it would have 

withdrawn its declaratory judgment claim from the state court and litigated it in this 
31 

Court[, which] is difficult to square with its decision to continue litigating in state court 

for at least ten months before taking any action in response to the assignment.” Predator, 

2014 WL 201662, at *5. But the court omitted an important component of Predator’s 

assertion. What Predator said was that if Gamo had informed Predator of the sale in 

June, “while Predator’s patent infringement claim was still pending” in federal court, 

Pl.’s Resp. to Defs.’ Mot. for Sanctions at 27, Predator Int’l, Inc. v. Gamo Outdoor USA, 

Inc., No. 1:09-cv-00970-PAB-KMT (D. Colo. Jan. 12, 2012) (emphasis added), it would 

have dismissed the state case and kept the infringement claim alive. Once the patent 

claim had been dismissed, however, there would be stronger reasons to continue with the 

state case, at least absent further complicating developments. We are not saying that the 

district court abused its discretion in denying the motion to supplement and amend 

because of Predator’s delay in bringing the motion. But in light of Predator’s asserted 

justifications, the delay did not make it objectively unreasonable for Predator to seek to 

add the claims. 

3. Standing 

Finally, the district court held that Predator had no basis to reassert its patentinfringement claim because it had no new evidence of standing. It stated that a lack of 

standing and a lack of evidence of standing is “a distinction without a difference,” 

Predator, 2014 WL 201662, at *5; but as discussed above, Predator had no obligation to 

prove standing conclusively at the pleading stage, see Lujan, 504 U.S. at 561. And 

whether or not it had been “[]prudent” for Predator to dismiss the claim in 2010, 
32 

Predator, 2014 WL 201662, at *5, later developments in the state-court litigation—such 

as the threat of complicated and prolonged proceedings—could have reasonably led 

Predator to reassess that determination. In particular, if Predator could not refile its 

infringement claim until it had proved its ownership of the patent in state court, then the 

longer the delay in state court (and the prospect of delay had increased as the state 

litigation expanded), the greater the chance that the statute of limitations on the 

infringement claim could reduce any recovery Predator might obtain against Gamo, a 

point specifically argued to the district court by Predator. In short, Predator’s standing 

was adequately supported by the allegations in the proposed amended complaint, and 

there were proper grounds for it to change its mind and now seek to litigate ownership in 

the federal court. Again, we do not suggest that denial of the motion to amend was an 

abuse of discretion, but only that the motion to amend was not unwarranted. 

In light of our determination that the Rule 11 sanction must be reversed, we need 

not address Cogswell’s other arguments for reversal, except to say that we reject the 

unfounded contention that the district judge was biased. 

II. CONCLUSION 

We REVERSE the district court’s judgment imposing sanctions on Cogswell and 

REMAND for further proceedings.