Document ID: s3://data.kl3m.ai/documents/govinfo/USCOURTS/USCOURTS-ca10-88-01596/USCOURTS-ca10-88-01596-0/pdf.json

Parties Involved:
Makita Electric Works, Ltd
Appellee
Makita, U.S.A., Inc.
Appellee
Gilbert J. Werth
Appellant
Kathleen L. Werth
Appellant

Document Text:

PUBLISH 

FILED 

United States Coprt <?f Appeals Tenth C1rcu1t 

IN THE UNITED STATES COURT OF APPEALS NOV 2 5 1991 

FOR THE TENTH CIRCUIT 

GILBERT J. WERTH and KATHLEEN L. WERTH 

husband and wife, Natural Parents and 

Legal Guardian of CHRIS WERTH, a minor, 

Plaintiffs-Appellants, 

v. 

MAKITA ELECTRIC WORKS, LTD., an Alien 

Company, located in the Country of Japan, 

and MAKITA, U.S.A., INC., a New York 

corporation, 

Defendants-Appellees. 

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ROBERT L. HOECKER 

Clerk 

No. 88-1596 

APPEAL FROM THE UNITED STATES DISTRICT COURT 

FOR THE DISTRICT OF KANSAS 

(D.C. Ho. 84-2762-K) 

Thomas c. Boone, Hays, Kansas, for Plaintiffs-Appellants. 

Thomas o. Baker of Baker & Sterchi, Kansas City, Missouri (Larry 

A. Withers of Kahrs, Nelson, Fanning, Hite & Kellogg, Wichita, 

Kansas, and Evan A. Douthit of Baker & Sterchi, Kansas City, 

Missouri, with him on the brief), for Defendants-Appellees. 

Before HOLLOWAY and EBEL, Circuit Judges, and KANE*, District • 

Judge. 

HOLLOWAY, Circuit Judge. 

* Honorable John L. Kane, Jr., Senior United States District Judge 

for the District of Colorado, sitting by designation. 

Appellate Case: 88-1596 Document: 010110097398 Date Filed: 11/25/1991 Page: 1 
This appeal is from a judgment, entered on a verdict directed 

at the conclusion of plaintiffs' evidence, in favor of the 

defendants-appellees Makita Electric Works, Ltd. and Makita, 

U.S.A. I Inc. (together Makita). The plaintiffs-appellants, 

Gilbert and Kathleen Werth suing on behalf of their minor son, 

brought this diversity products liability action in the United 

States District Court of the District of Kansas. 1 The claims of 

error focus on the trial judge's exclusion of the proffered 

testimony of two of plaintiffs' expert witnesses. We agree that 

rejection of the evidence was error and reverse. 

I. THE FACTUAL BACKGROUND 

This personal injury lawsuit arises from an accident 

involving a Makita Model 5007NB, 71⁄4 inch circular saw, 

manufactured and distributed by Makita. The incident occurred on 

April 11, 1984, when sixteen year old Chris Werth ("Chris") was 

cutting wood paneling in the workshop on his family's farm. As 

developed at trial, Chris was experienced in the use of power 

tools, including circular saws, having used them at the farm and 

at school without previous mishap. 

On the day of the incident, Chris placed a 4' x 8' x 1/8" 

sheet of paneling over two tables of unequal height, positioned 

approximately three feet apart, and marked the cut to be made. 

Using the recently purchased Makita saw, Chris began sawing along 

1 

Defendant-appellee Makita Electric Works, Ltd. is a Japanese 

corporation located in Anja, Japan. Defendant-appellee Makita, 

U.S.A., Inc., is a New York corporation with its principal place 

of business in New York. Plaintiffs-appellants are citizens of 

Kansas. 

2 

Appellate Case: 88-1596 Document: 010110097398 Date Filed: 11/25/1991 Page: 2 
the mark. He held the saw in his left hand, and steadied the wood 

with his right, which was placed to the right of the mark on top 

of the wood. The paneling was not clamped or otherwise affixed to 

the tables. 

After cutting in approximately ten to twenty inches, Chris 

noticed the paneling was vibrating. While holding the running saw 

in place with his left hand, Chris shifted his body position and 

moved his right hand backward to steady the wood. He does not 

remember where he placed his right hand or exactly what happened 

next. He does recall, however, that upon resumption of the 

forward cut, his right hand became "tangled up into" the saw. 

Chris' brother, Michael, was working nearby outside the workshop. 

He heard Chris scream and rushed to the workshop. Chris was taken 

to a hospital where it was determined that his right index and 

small finger had been completely severed from his hand, and the 

two fingers between were attached only by strips of skin on the 

back of his hand. The doctors were only able to reattach Chris' 

two middle fingers. 

The complaint against Makita alleges that Makita was 

negligent in the design, inspection, testing and other 

manufacturing aspects of the saw (Count I); Makita was strictly 

liable for Chris' injuries because the circular saw was defective 

in that it was not equipped with either a blade brake or a riving 

knife, 2 and because the saw's instruction manual contained 

2 

A "blade brake" is designed 

rotation of the circular saw 

released. See IV R. at 59. 

to quickly slow and stop the 

blade after the saw's trigger is 

A "riving knife" is a thin, 

(Footnote continued on next page) 

3 

Appellate Case: 88-1596 Document: 010110097398 Date Filed: 11/25/1991 Page: 3 
inadequate warnings and instructions (Count II), and; Makita 

breached express and implied warranties (Count III). Following 

discovery, plaintiffs elected to proceed solely on the strict 

liability claim in Count II. They alleged a 45% permanent 

disability to Chris' right hand, and sought medical expenses, lost 

earnings, compensatory and punitive damages, and costs. 

By a motion in limine, Makita sought to preclude the 

testimony of plaintiffs' expert, Gary Robinson, asserting he was 

not qualified under Fed. R. Evid. 702 to testify on the proper 

design, function or operation of circular saws, blade brakes, or 

riving knives. Makita also challenged the adequacy of the factual 

basis for Robinson's opinion under Fed. R. Evid. 703. The court 

took this motion under advisement. Similar objections were made 

to testimony by plaintiffs' other 

Bertolett. 

leading witness, Craig 

In opening argument at the jury trial, plaintiffs' counsel 

described the accident as resulting from a "kickback" of the saw, 

caused by a binding of the wood on the rotating blade which forced 

the sawblade up out of the kurf 3 and into contact with Chris' 

hand. Counsel contended that installation of either a blade brake 

or riving knife would have lessened or prevented Chris' injuries. 

(Footnote continued): 

wedge-shaped metal attachment to the rear of the saw which follows 

the blade through the cut made by the saw in the wood. See id. at 

68, 75. 

3 

The "kurf" is a technical name for the cut made by the saw in 

the wood. II R. at 71. 

4 

Appellate Case: 88-1596 Document: 010110097398 Date Filed: 11/25/1991 Page: 4 
In response, Makita's counsel said that their evidence would show 

that a kickback could not have occurred under the facts of this 

case. Specifically, Makita claimed that the type of cut received 

by Chris (palm-side as opposed to back-of-the-hand) was 

inconsistent with the view that a kickback occurred. Instead, 

defendants asserted that the sole cause of the accident was Chris' 

carelessness in putting his hand under the paneling, where it was 

exposed to the sawblade. Makita also argued they would show that 

use of either of the two suggested safety devices would not have 

prevented the accident. 

Chris testified about the circumstances of the incident as 

described above. III R. at 5-112. He could not recall exactly 

how his hand made contact with the sawblade. Id. at 31, 34. 

Chris did state that immediately preceding the accident the saw 

appeared to function normally and that after he started the cut he 

did not recall anything which suggested that the blade was binding 

in the wood. He also said that he did not see the saw come out of 

the kurf. Id. at 91, 111-12. Because he did not remember exactly 

what happened, he conceded that it was possible that he had placed 

his hand under the wood when steadying it, as the defense 

contended. Id. at 109-10. 

Plaintiffs' witness Pilens, sales manager at a Wichita store 

selling saws similar to the Makita saw, testified that the 

vibration of the wood experienced by Chris was the result of a 

4 "[b]inding of some sort." IV R. at 82. On cross examination, 

4 

On cross examination of Pilens, the court permitted defense 

(Footnote continued on next page) 

5 

Appellate Case: 88-1596 Document: 010110097398 Date Filed: 11/25/1991 Page: 5 
however, Pilens conceded that neither a blade brake, nor a riving 

knife, would have prevented a kickback had the binding been at the 

front of the blade. Id. at 67, 74. He did note, however, that a 

riving knife could prevent a hand placed under the wood from 

contacting the rear of the blade. See id. at 98. 

Plaintiffs' medical expert, Dr. Tyrone Artz, an orthopedic 

surgeon, testified that Chris .suffered an oblique, palm-side cut 

to his right hand, caused by an all-at-once contact with the 

sawblade. II R. at 128-30. Plaintiffs next called Chris' 

brother, Michael, who testified about the conditions of the 

workshop immediately following the incident, including the 

location of the severed fingers and the pattern and location of 

blood he observed. IV R. at 164-177. 

Plaintiffs then sought to present the expert opinions of 

Robinson and Bertolett who were to testify that the saw's design 

was unreasonably dangerous. Makita renewed its objection to the 

testimony of Robinson and objected to that of Bertolett, asserting 

both would be merely speculating as to the cause of the accident. 

Following voir dire of both experts, the trial court refused to 

let either testify as to the defectiveness of the saw. Plaintiffs 

then rested, and the court granted Makita's motion for a directed 

verdict. Plaintiffs' subsequent motion for a new trial was 

denied. Plaintiffs appeal, asserting errors in the exclusion of 

(Footnote continued): 

counsel to treat him as an expert on circular saws due to his 

former experience as a power tool repairman. See IV R. at 57-81, 

89. 

6 

Appellate Case: 88-1596 Document: 010110097398 Date Filed: 11/25/1991 Page: 6 
their experts' testimony and the direction of a verdict for 

Makita. 

II. DISCUSSION 

A. Timeliness of the Notice of Appeal 

We will briefly deal with Makita's claim that the notice of 

appeal was untimely under Fed. R. App. 3 and 4. The gist of 

Makita's argument is that plaintiffs' motion for a new trial was 

defective because it failed to comply with Fed. R. Civ. P. 7(b) 

and the district court's local rule 206(a). Since a defective 

motion for a new trial is considered void, Makita argues, the 

filing of a defective motion for a new trial does not toll the 

time for filing a notice of appeal, making plaintiffs' April 6 

filing untimely. 

Fed. R. Civ. P. 7(b) requires that a motion shall "state with 

particularity the grounds therefor, and shall set forth the relief 

or order sought." In Fine v. Paramount Pictures, 181 F.2d 300 

(7th Cir. 1950), the court held that an oral motion for a new 

trial, which was timely made but defective for failing to state 

any ground for relief with sufficient particularity, did not toll 

the time for appeal. But see Witt v. Merrill, 208 F.2d 285 (4th 

Cir. 1953) (motion for new trial without assignment of reasons was 

effective to toll running of time for appeal because trial court 

entertained the motion and granted leave to file a brief in 

support thereof). 

Plaintiffs' motion for a new trial here does state 

assignments of error concerning its principal claim of error on 

7 

Appellate Case: 88-1596 Document: 010110097398 Date Filed: 11/25/1991 Page: 7 
appeal -- the exclusion of the expert's . . 5 opinions. Makita's 

assertion that "[t]hese contentions are nothing more than 

conclusory, general allegations that fail to satisfy the Rule 7(b) 

requirement" is unconvincing. Although plaintiffs' assignments of 

error are made in general terms, they clearly state the particular 

grounds relied on, namely the trial court's refusal to permit two 

particular experts to testify. Thus the motion sufficiently 

complies with the requirements of Rule 7(b) to toll the running of 

the time for appeal. See 2A Moore's Federal Practice, 1 7.05 at 

7-15, 7-16 (1984) (noting that the particularity requirement is 

"flexible" and that "reasonable specification is all that the 

requirement of particularity imposes"); Witt v. Merrill, 208 F.2d 

285, 286 (4th Cir. 1953) (motion for new trial cannot be deemed a 

nullity where trial judge entertained it, continued it for 

5 

The motion states in part: 

1. That the Court erred when it sustained the 

objections of the Defendants to the opinions of Gary 

Robinson and Craig Bertolett, the Plaintiff's two 

experts herein for the reason that said ruling is 

contrary as it [sic] dictates to Federal Rules of 

Evidence 702, 703 and 704. In support of this motion 

for new trial ... Plaintiff submits the written 

proffer filed herein by the Plaintiff, ... and the 

sworn testimony of Gary Robinson .•. [and of] Craig 

Bertolett proffered after the Courts [sic] ruling on the 

same date, and 

2. Plaintiff further urges a new trial for the reason 

that in analyzing the Court's ruling on Gary Robinson 

and Craig Bertolett, the Court was in effect, as part of 

its ruling herein, literally sustaining a motion to 

dismiss on the grounds that the Plaintiff was guilty of 

contributory negligence contrary to dictates of K.S.A. 

60-258(a). 

IR. Doc. 60 at 1-2. 

8 

Appellate Case: 88-1596 Document: 010110097398 Date Filed: 11/25/1991 Page: 8 
\ \ 

arguments, and permitted parties to file briefs addressing it). 

Makita's second argument is also meritless. Makita says that 

plaintiffs failed to comply with Local Rule 206(a) by failing to 

attach a brief or memorandum to the new trial motion, which makes 

the motion void ab initio. Rule 206(a) of the Rules of Practice 

of the District of Kansas provides that, with certain exceptions, 

all motions filed with the clerk 

shall be accompanied by a brief or memorandum unless 

otherwise provided in these rules. With the approval of 

the court, parties may be relieved from the requirement 

of serving and filing written briefs or memoranda in 

support of motions, responses and replies. 

D. Kan. R. 206(a) (1988). Plaintiffs conceded at the hearing on 

their motion for a new trial that they failed to comply with the 

local rule. See Tr. 2/24/88 at 2. However, the trial court 

agreed to and did hear plaintiffs' motion for a new trial and thus 

relieved plaintiffs of the requirements of Rule 206(a). 6 Makita 

did not object to the form of the motion or to the court's 

decision to consider it. Plaintiffs' motion was clearly brought 

6 

After plaintiffs' counsel, Mr. Boone, advised the judge that 

he had filed "a motion without a memorandum," the following 

dialogue occurred: 

The Court: 

Mr. Boone: 

That's what I had. 

I think -- well 

The Court: It suffices for the purpose of --

Mr. Boone: I understand. 

know what 

position is, . 

Tr. 2/24/88 at 2 (emphasis added). 

9 

I 

the issues 

think 

are, 

we 

what 

all 

my 

Appellate Case: 88-1596 Document: 010110097398 Date Filed: 11/25/1991 Page: 9 
to the attention of the district court, it was opposed by Makita, 

and it was heard and ruled on at the formal hearing. 

We hold that the objections to the timeliness of the notice 

of appeal are without merit. 

B. Exclusion of the Expert Testimony 

On the merits, plaintiffs argue that the district court erred 

in excluding the testimony of experts Robinson and Bertolett. 

Generally a trial judge's ruling on the admission or exclusion of 

expert testimony will not be overturned unless it is manifestly 

erroneous or an abuse of discretion. Kloepfer v. Honda Motor Co., 

Ltd., 898 F.2d 1452, 1458 (10th Cir. 1990); Sil-Flo, Inc. v. 

SFHC, Inc., 917 F.2d 1507, 1517 (10th Cir. 1990) (same). We turn 

to the procedural and then the substantive law relevant to the 

expert testimony in question here. 

1. Standards Governing Admission of the Evidence 

The admission of expert testimony is guided in federal court 

by the Federal Rules of Evidence, particularly here rules 702 and 

703. Rule 702 provides: 

If scientific, technical, or other specialized knowledge 

will assist the trier of fact to understand the evidence 

or to determine a fact in issue, a witness qualified as 

an expert by knowledge, skill, experience, training, or 

education, may testify thereto in the form of an opinion 

or otherwise. 

Fed. R. Evid. 702. 

Thus, the "touchstone" of admissibility is helpfulness to the 

trier of fact. See Breidor v. Sears, Roebuck & Co., 722 F.2d 

1134, 1139 (3rd Cir. 1983). Moreover, "a lack of specialization 

does not affect the admissibility of the [expert's] opinion but 

only its weight," Wheeler v. John Deere Co., 935 F.2d 1090, 1100 

10 

Appellate Case: 88-1596 Document: 010110097398 Date Filed: 11/25/1991 Page: 10 
(10th Cir. 1991), although "a[n expert] witness must have skill or 

experience in the matter to which the subject relates." Petition 

of Central Kansas Elec. Co-op, Inc., 582 P.2d 228, 236 (Kan. 

1978); see also Wheeler, 935 F.2d at 1100 (noting that an expert 

must "stay within the reasonable confines of his subject area"). 

As we have noted, "[t]he test expressed in Rule 702 -- will the 

expert testimony 'assist the trier of fact to understand the 

evidence or to determine a fact in issue' -- emerges as the 

central concern of Article VII [of the Federal Rules of Evidence]. 

Although there were more restrictions on opinion evidence before 

the enactment of the Federal Rules, helpfulness to the trier of 

fact was seen then as an essential condition of admissibility." 

Specht v. Jensen, 853 F.2d 805, 807 (10th Cir. 1988) (en bane) 

(quoting 3 Weinstein's Evidence, ,r 702 [01] (1985)), cert. denied, 

488 u.s. 1008 (1989). 

Rule 703, which describes the appropriate bases for expert 

opinions, provides: 

The facts or data in the particular case upon which an 

expert bases an opinion or inference may be those 

perceived by or made known to him at or before the 

hearing. If of a type reasonably relied upon by experts 

in the particular field in forming opinions or 

inferences upon the subject, the facts or data need not 

be admissible in evidence. 

Fed. R. Evid. 703. Simply stated, this rule lists three bases for 

expert opinion testimony: 1) the expert may gather information by 

firsthand observation; 2) the expert may base his or her 

testimony on facts presented at trial by hypothetical questions of 

counsel, or facts from evidence before the court; and 3) the 

expert may rely on facts outside the record and not personally 

11 

Appellate Case: 88-1596 Document: 010110097398 Date Filed: 11/25/1991 Page: 11 
observed, but of the kind that experts in his or her field 

reasonably rely on in forming opinions. See Ponder v. Warren Tool 

Corp., 834 F.2d 1553, 1557 (10th Cir. 1987); Ramsey v. Culpepper, 

738 F.2d 1092, 1101 (10th Cir. 1984). Moreover, as we noted in 

Ponder, expert testimony on causation "otherwise admissible is not 

objectionable because it embraces an ultimate issue to be decided 

by the trier of fact." Id. at 1557 (quoting Fed. R. Evid. 704). 

2. The Substantive Kansas Law 

Under the governing law of Kansas, 7 to establish a prima 

facie strict liability case plaintiffs must prove three elements: 

"(1) the injury resulted from a condition of the product; (2) the 

condition was an unreasonably dangerous one; and (3) the 

condition existed at the time it left the defendant's control." 

Mays v. Ciba-Geigy Corp., 661 P.2d 348, 360 (Kan. 1983). As 

further explained by the Kansas Supreme Court: 

These elements may be proven inferentially, by either 

direct or circumstantial evidence. For circumstantial 

evidence to make out a prima facie case, it must tend to 

negate other reasonable causes, or there must be an 

expert opinion that the product was defective. Because 

liability in a products liability action cannot be based 

on mere speculation, guess or conjecture, the 

circumstances shown must justify an inference of 

probability as distinguished from mere possibility. 

Id. (emphasis added). 

Here, as plaintiffs' counsel conceded in his opening 

argument, and as shown by subsequent testimony, Chris was the 

only witness to the incident and he was unable to remember some of 

7 

To the extent that any of the trial judge's rulings were 

based on the law of Kansas, we review those state law rulings de 

novo. See Salve Regina College v. Russell, U.S. __ , 111 

S. Ct. 1217, 1221 (1991). 

12 

Appellate Case: 88-1596 Document: 010110097398 Date Filed: 11/25/1991 Page: 12 
the details himself. See II R. Doc. 79 at 72; III R. at 31, 34. 

Therefore, as to the first element of plaintiffs' case, plaintiffs 

offered circumstantial evidence and the testimony of the experts, 

along with Chris' testimony, to show that a defect in the Makita 

saw caused Chris' injuries. See, e.g., Campbell v. Clark, 283 

F.2d 766, 770 (10th Cir. 1960) (reconstruction used when injured 

plaintiff was the sole witness and could not recall details). 

We turn to the district court's rejection of the testimony of 

each expert in turn. 

Gary Robinson 

Plaintiffs first called Gary Robinson as an expert witness, 

who was hired to investigate the accident. Robinson testified 

extensively about his qualifications, recounting his education and 

his experience as a safety consultant. 8 Robinson testified that 

his investigation of the instant case involved a visit to the 

Werth farm, where he inspected and photographed the workshop and 

8 

Robinson, a Michigan State University graduate, testified 

about his expertise in power tool safety, stating that he had 

served approximately 15 years as the president of two safety 

consulting firms. He also recounted his five-year experience as 

the Safety Director for the Pontiac Motors Division of General 

Motors Corporation, and his seven years' work as a safety engineer 

for GMC and two insurance companies. See V R. at 4-26. 

Although the defendants asserted in their in limine motion 

that Robinson lacked sufficient educational or professional 

qualifications to offer his opinion on the saw's defectiveness, 

see I R., Doc. 45 at 3, the record clearly shows that the trial 

court did not exclude Robinson's testimony on this basis. 

Plaintiffs' counsel specifically asked the court about this 

objection following the ruling.on Robinson, to which the court 

replied: "I would think that Mr. Robinson has considerable 

expertise in safety analysis and in the safeguardings [sic] of 

appliances or equipment or tools. That's not the reason I entered 

my findings. " V R. at 85. 

13 

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the saw, and interviewed the Werth family, including Chris. V R. 

at 41-49. 

At this point, plaintiffs' counsel posed two questions to 

Robinson, the first, calling for his expert opinion whether the 

Makita saw met "good guarding principles," and the second, asking 

whether the saw had a "defect in its design which rendered it 

unreasonably dangerous to the user?" V R. at 75-76, 77. Defense 

counsel objected to both questions. During the subsequent voir 

dire, the trial judge asked Robinson how he defined the concept of 

"unreasonably dangerous." Robinson responded: "I define it if 

the risk can be reduced to an acceptable level, and if it is not, 

then it's unreasonably dangerous from a safety standpoint. 

Acceptable level means within technology, cost effectiveness and 

its effect on production." V R. at 78. Following this answer, 

Robinson was barred from giving further expert testimony in this 

case. 

The trial court cited two reasons for excluding Robinson's 

testimony. First, the court noted that he would not permit 

Robinson to testify because "the test that Mr. Robinson has 

tendered is not the [strict liability] test of Kansas." V R. at 

78. The court explained that under Kansas law, a product is 

unreasonably dangerous "if it is dangerous to the extent beyond 

that which would be contemplated by [an ordinary] .•. consumer." 

Id. The court cited Lester v. Magic Chef, 641 P.2d 353 (Kan. 

1982), as authority for its conclusion that the proper test in 

Kansas is the "consumer-expectation" test. V R. at 111. Second, 

the court barred Robinson's testimony because he was not qualified 

14 

Appellate Case: 88-1596 Document: 010110097398 Date Filed: 11/25/1991 Page: 14 
to "reconstruct" the accident in that he had failed to conduct 

independent testing of the saw and material when given the chance 

at the Werth farm and later. See id. at 83-84. The court held 

that without independent tests, Robinson's testimony would be 

"speculative," and thus, was inadmissible. Id. Specifically, the 

judge ruled: 

[N]otwithstanding whatever qualifications 

[Robinson] has and his interest in the safety standards 

or guarding, he's really here to reconstruct what 

happened .... I will sustain the objection as to the 

admissibility of the witness's [sic] testimony because 

other than that is to ask this Court and this jury to 

speculate. 

My reasons for this are that Rule 704 or 702 is 

[sic] that I should permit a witness to testify as an 

expert if his scientific, technical or specialized 

knowledge will assist the trier of fact, the jury here, 

to understand the evidence or to determine a fact in 

issue .... [I]t's my policy and practice that expert 

witness's [sic] should not be permitted to speculate as 

to what happened when they had the opportunity to test 

that thesis and have not done so. That's the case here. 

This witness then must first establish what happened. 

First part of vour question is based on how this 

happened, and to tell us here how it happened is 

speculation. So, I will sustain the objection. 

Id. at 83-84 (emphasis added). 

We believe the court abused its discretion in excluding 

Robinson's answers to the propounded questions, despite its 

correct appraisal that the consumer-expectation test governs in 

Kansas. See Magic Chef, 641 P.2d at 357, 361; Barnes v. Vega 

Indus., Inc., 676 P.2d 761 (Kan. 1984); Betts v. General Motors 

Corp., 689 P.2d 795, 801 (Kan. 1984). Although the court properly 

intercepted Robinson's initial testimony which was based upon the 

wrong legal standard, see, e.g., Karns v. Emerson Electric Co., 

( 817 F.2d 1452, 1459 (10th Cir. 1987) (expert's use of legal terms 

15 

Appellate Case: 88-1596 Document: 010110097398 Date Filed: 11/25/1991 Page: 15 
must not conflict with the court's instructions), we find no 

support for the continued rejection of Robinson's testimony since 

counsel corrected his questions, using the right legal standard. 

See, e.g., Lawrence v. Texas, 457 S.W.2d 561, 562 (Tex. Crim. App. 

1970) (noting that "where a question has been improperly put, 

counsel may propound a proper question free from the defects in 

the former question"). 

During the subsequent offer of proof, plaintiffs' counsel 

specifically described to Robinson Kansas' "consumer-expectation" 

test and asked Robinson whether he had an opinion about the saw's 

defectiveness under that test. V R. at 103-04. Robinson opined 

that he still found that the saw was "unreasonably dangerous." 

Id. at 103. Nevertheless, the court again refused to permit him 

to testify, stating that he would not allow Robinson "to roll with 

the caselaw and somehow make your conclusions" under the correct 

legal standard. V R. at 112. 

Certainly, the court, and not an expert, instructs the jury 

on the proper legal standard to apply. See Specht, 853 F.2d at 

807 (noting that "it is axiomatic that the judge is the sole 

arbiter of the law and its applicability"). However, the correct 

legal standard having been identified, and an inquiry having been 

made thereunder about the saw based on the relevant circumstances, 

we cannot sustain the trial judge's refusing to admit the 

testimony proffered under the right standard. In the absence of 

any showing of misconduct or misrepresentation by either 

plaintiffs' counsel or Robinson, the court erred by rejecting the 

plaintiffs' proper offer of proof under Kansas law. 

16 

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As to the court's second reason to exclude Robinson's 

testimony, the question which the ruling raises is whether a 

per se rule exists which requires an accident reconstruction 

expert to conduct independent tests before an opinion on causation 

is admissible. No authority supporting such a rule was cited and 

we find none. We hold that it was error for the district court to 

have imposed such a requirement of independent tests. 

In Wylie v. Ford Motor Corp., 502 F.2d 1292 (10th Cir. 1974), 

a diversity products liability case, plaintiff presented the 

testimony of an expert physicist in order to explain why his 

automobile went out of control, crashing and injuring him. The 

expert testified that he believed the car's control arm was 

defective because the ball joint had abnormally worn down, 

permitting the ball to separate from the socket and causing the 

accident. Despite this testimony, the district court directed a 

verdict for Ford. We reversed. Although the context of the Wylie 

decision differs slightly from the present case, in reversing the 

district court's grant of a directed verdict, we held that the 

expert's failure to conduct independent tests went only "to the 

weight which the trier of fact should accord the evidence and 

[did] ... not make the testimony incredible." Id. at 1294. 

Thus, in Wylie, we accepted the view that otherwise relevant, 

factually related expert opinion evidence could support a products 

liability claim despite the fact that the expert did not conduct 

independent tests. Fed. R. Evid. 703, cited by the district 

court, makes no mention of a requirement of independent tests. 

Rather, Rule 703 and Rule 704 clearly contemplate an "opinion," 

17 

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and not only a recitation of facts observed from independent 

testing. See, e.g., Lollis v. Superior Sales Co., Inc., 580 P.2d 

423, 428 (Kan. 1978) (expert opinion reconstructing accident 

especially helpful where there are no eyewitnesses). 9 

As shown during an oral proffer made immediately following 

the court's ruling, Robinson identified three possible scenarios 

which could have resulted in the accident. The first was 

plaintiffs' primary theory of kickback; the second, was 

defendant's theory that Chris simply put his hand under the 

paneling and hit the back of the blade; and the third, that "the 

material itself might have gone forward, leaving the saw 

stationary, and, therefore, his hand being on the material would 

come in contact with the rear of the blade." V R. at 101-02. 

In support of the trial court's ruling, defendants contend 

Robinson's opinion was properly deemed "speculative" because he 

9 

Under Kansas law, expert testimony on the defectiveness of a 

product is not preconditioned on "establish[ing] what happened," 

as the trial judge said here in rejecting Bertolett's testimony. 

The Kansas court has noted that such a cause of action may be 

proved by circumstantial evidence which need not rise to the level 

of certainty of excluding any and every other reasonable 

conclusion. It is proper to use expert testimony to prove 

causation, provided that the expert's opinion is based on adequate 

facts and not upon evidence which is too uncertain or speculative. 

See Mays v. CIBA - Geigy Corp., 661 P.2d at 360. "[T]he 

circumstances shown must justify an inference of probability as 

distinguished from mere possibility." Id. at 360. 

We also note that the same expert involved in this case, Gary 

Robinson, has testified on causation in another products liability 

case that eventually reached the Kansas Supreme Court See Siruta 

v. Hesston Corp., 659 P.2d 799 (Kan. 1983). Siruta is similar to 

the instant case in that the plaintiff there, as here, was unable 

to recall exactly what caused the accident. The Kansas Supreme 

Court found Robinson qualified to testify on both defectiveness 

and causation, noting that his opinion was adequately based upon 

the plaintiff's statement and an inspection of the machine at 

issue. See id., 659 P.2d at 807. 

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could not identify which of the three scenarios actually happened. 

See Appellee's Brief at 10. However, as we read the record, 

Robinson's theory of defectiveness was based on a clear 

probability of what happened in that no version of events other 

than these three was ever argued to have occurred. As Robinson 

later noted in the proffer: "if a riving knife had been on [the 

Makita saw] it[] would have been, in fact, a barrier and the 

accident wouldn't have happened, no matter which of the three 

reconstructions occurred." Id. at 108 (emphasis added). Thus, 

Robinson's expert opinion on the defectiveness of the saw was 

based on three permissible views of what happened, all consistent 

with the evidence presented. 

Under Kansas strict liability in tort principles, the 

question is whether the inference of causation is too speculative. 

See Ciba-Geigy, 661 P.2d at 360; Siruta v. Hesston Corp., 659 

P.2d 799, 805-06 (Kan. 1983) (holding that a reasonable inference 

that a machine belt broke and pulled plaintiff into the machine 

could support expert testimony on the defectiveness of the machine 

even though "[i]t all happened so fast that plaintiff could not 

remember exactly how it happened but that is his recollection"). 

The evidence presented at trial here made the three possibilities 

mentioned by Robinson the only three legitimate inferences. As 

shown by the proffer, Robinson's opinion on the defectiveness of 

the saw was the same regardless of which of the three actually 

occurred. Having expressed his opinion based on the implicit 

elimination of any other possible causes, Robinson should have 

been permitted to respond if his opinion would have assisted the 

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jury. See, e.g., Farmer's Insurance Co. v. Smith, 549 P.2d 1026, 

1032-34 (Kan. 1976) (investigator's opinion that fire was caused 

by a defective loose connection should have been admitted despite 

his inability to physically find the connection where he formed 

this opinion by process of elimination); Briedor, 722 F.2d at 

1138-39 (noting that "[w]here there is a logical basis for an 

expert's opinion testimony, the credibility and weight of the 

testimony is to be determined by the jury, not the trial judge"). 

Because the jury did not have Robinson's knowledge of industrial 

safety practices and standards concerning circular saws, his 

testimony would have been helpful and should have been admitted 

under the test of Rule 702. See Specht v. Jensen, 853 F.2d at 

807. 

In addition to explaining the three ways the accident could 

have occurred, Robinson's testimony was also offered to support 

plaintiffs' claim of defective design under a "failure to guard" 

theory. As Robinson stated in the proffer: 

It's a machine guarding case because I believe basically 

this case is a riving knife case. The purpose of a 

riving knife is two-fold: One, to eliminate or reduce 

the possibility of kickback. Secondly, and just as 

importantly, it acts as a barrier guard between the rear 

of the blade where most of the accidents occur and the 

operator, and placing a barrier in the rear of the 

circular saw in the form of a riving knife is, in fact, 

a machine guarding principle and concept. 

V R. at 106. 

This court has recently noted, "[w]hile under the Federal 

Rules of Evidence a district court has substantial discretion in 

deciding which experts can and cannot testify, the district court 

may not employ this discretion to restrict viable and relevant 

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theories offered by a party." Graham v. Wyeth Laboratories, 906 

F.2d 1399, 1408-09 (10th Cir.), cert. denied, 111 s. Ct. 511 

(1990). Both the "failure to guard" and kickback theories 

supported plaintiffs' strict liability claim and could properly be 

used to prove that claim. Therefore, under Wyeth Laboratories, 

the exclusion of Robinson's testimony cannot be considered 

harmless. In sum, we are convinced that the trial judge erred in 

excluding Robinson's testimony and abused his discretion by so 

doing. 

Craig Bertolett 

Plaintiffs also offered the expert testimony of Craig 

Bertolett, a consulting engineer who had worked extensively in the 

design and development of hand-held circular saws, and who had 

experience in reconstructing the kickback phenomenon. VI R. at 

4-21, 65. 10 Like Robinson, Bertolett had gone to the Werth farm 

following the accident. Bertolett examined and photographed the 

workshop and the saw, and interviewed the family. 

25-29, 38-49. 

See id. at 

Bertolett's expert opinion was tendered as a means of 

explaining how Chris' injury occurred. As Bertolett testified, "I 

10 

Bertolett's impressive qualifications include graduate 

degrees in mechanical engineering (New Mexico State University), 

business administration (Loyola College, Maryland), and a 

bachelor's degree from the United States Military Academy at West 

Point, and extensive experience. He was employed at Black & 

Decker for six years, serving as Project Engineer, Manager of 

Resident Engineering, and then Director of "Test and Evaluation." 

At Black & Decker, he supervised the design, design changes, and 

testing of products, including circular saws. Bertolett also 

worked four years as Vice President of Engineering for the Special 

Products Division of Emerson Electric Company before forming his 

own engineering consulting firm in 1980. VI R. at 4-21. 

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asked [Chris] to help me reconstruct the accident at the site." 

Using the same workshop tables and a facsimile sheet of wood, 

Bertolett and Chris "very deliberately arranged the saw, the table 

[sic] and photographed the situation." Id. at 29. Bertolett also 

interviewed both Chris and his brother to determine the location 

of the severed fingers and the blood splashes. Id. at 47-49. 

After developing Bertolett's technical experience and his 

study of the kickback phenomenon, plaintiffs' counsel asked: "Do 

you have an opinion, sir, as to what happened to Chris Werth when 

he was in the progress [sic] of the cutting of his plywood when he 

lost his fingers?" Defense counsel immediately objected on the 

bases of relevancy and that the question "calls for speculation." 

VI R. at 71. Voir dire followed. During the voir dire, Bertolett 

conceded that he did not know exactly how the binding took place. 

Id. at 73. He also stated that although he had plugged in and 

started the Makita saw at the Werth farm, he did not run any tests 

or cut wood with that saw. Id. at 74-75. 

After the voir dire and the arguments of counsel, the judge 

stated, in relevant part: 

At best we know from Chris Werth that he doesn't know 

what happened •..• He did testify that he did not 

recall anything unusual happening with regard to the 

saw, nor did he recall a kickback. 

Now, having said that, there isn't much that any 

witness can draw upon to tell us what did happen. 

You're asking this witness to tell this jury what did 

happen. This witness has been to the scene, this 

witness is shown to have expertise in circular saws, and 

has expertise apparently as to the causes of kickback. 

And this witness was permitted the opportunity to 

simulate all the events that transpired, including the 

use of the tables, the placement of the board on the 

table, and he did that. But the one thing that is clear 

to me he did not do was simply to turn on the saw and 

put to the test what happens ones [sic] he commences to 

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saw into the wood. 

I would insist that he test that thesis, and to do 

anything other than that, ... , is to speculate, and, 

in my view his testimony is speculation and to reach an 

opinion as to what happened as you have asked him would 

be no more than speculation. 

Id. at 83-84 (emphasis added). Immediately before plaintiffs' 

subsequent proffer of Bertolett's testimony, the court further 

elaborated: 

All I can say is as of this moment this witness is 

not shown to know what happened, other than, in my view, 

to speculate .... [I]t's because of my own problem 

with experts· who are willing to postulate as to what 

they think happened once they are aware that they 

needn't rely upon the evidence at hand to draw that 

opinion, and I'm absolutely satisfied that given the 

opportunities to inspect and test their thesis, as 

legitimate experts ought to do, the answers are ofttimes 

are quite different. When they have at hand the 

opportunity here to put to the test their thesis and 

don't do so, in my view then they are not going to meet 

the [Fed. R. Evid.] 703 test if that question is somehow 

to be helpful to the jury[.] 

Id. at 90-91 (emphasis added). 

The underscored passages show that as with Robinson, 

Bertolett was precluded from testifying by the trial judge's 

application of an erroneous, per se rule requiring independent 

testing for accident reconstruction. On the authorities and 

reasoning relied on earlier, we are convinced that the judge erred 

in imposing such a precondition to the expert testimony. 

We have considered the circumstances on which Bertolett's 

proffered testimony was based. During the proffer, Bertolett 

explained what facts he used to support his opinion that a 

kickback occurred: 

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(By plaintiffs' counsel) 

Q: Was the blood significant to you in determining 

whether or not a kickback occurred? 

A: [W]here the blood was indicated that the cut took 

place above the workpiece. 

Q: 

A: 

Q: 

A: 

Q: 

A: 

Q: 

A: 

Above the plywood? 

Yes. And, therefore, by the definition of 

kickback, the accident took place with the blade 

above the work piece. 

Why is the blood relevant in that regard? 

The blood was at the end of the kurf on top of the 

board, which means it was thrown. The fingers 

none of them were underneath the board; therefore, 

they were thrown away, and one of them was thrown 

forward. which is consistent with the direction of 

the blade, and was thrown some great distance, not 

downward. That indicates to me another reason that 

it was that way. 

Above the work piece? 

Yes, right. The splattering on the wall indicated 

that might have actually rotated the thing •..• 

Concern you that Chris Werth doesn't remember any 

evidence of a kickback? 

[H]e sure as hell has in mind that his hand was 

entangled, and where the blood was and where the 

fingers were clearly indicate the accident was 

above the work piece. 

Id. at 95-97 (emphasis added). 

We cannot agree with the trial judge that such testimony 

should have been rejected as speculative. As noted in the 

proffer, Bertolett's analysis and his conclusion on kickback 

rested on facts already in evidence -- how the workpiece was set 

up, where the blood was splattered, and where the fingers were 

thrown. Such data clearly satisfied Rule 703 on the bases for 

opinion testimony. Bertolett learned these facts when he 

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interviewed Chris and Michael at the farm, and they were presented 

at trial when Michael testified. We cannot agree that it was 

impermissible speculation for Bertolett, with his qualifications, 

to form an opinion on the probable causation from his analysis of 

the facts indicating where the blood and fingers were thrown by 

the saw. 

Moreover, the doubts suggested by the trial judge concerning 

the sufficiency of the factual basis to support Bertolett's 

opinion go to its weight, and not to its admissibility. See, 

Quinton v. Farmland Indus., Inc., 928 F.2d 335, 337-38 (10th Cir. 

1991) (though doctor's factual knowledge was not "as complete as 

it might have been" it was "sufficiently detailed ... to permit 

his expression of an opinion as to the cause of the damages 

allegedly incurred"). Here the trial judge found Bertolett to 

have expertise on both circular saws and the causes of kickback. 

VI R. at 83. Such expertise necessarily subsumes some knowledge 

of how objects contacting a moving circular saw blade would react 

and where they would be thrown. 

Given the technical nature of the kinetic principles 

involved, we are persuaded that the testimony would have been 

helpful and should have been admitted for the jury to weigh under 

Rule 702. See Specht v. Jensen, 853 F.2d at 807. The exclusion 

of the critical testimony of the experts, Robinson and Bertolett, 

created an undue hardship, affecting plaintiffs' substantial 

rights. See Graham v. Wyeth Laboratories, 906 F.2d at 1408-09 

(exclusion of viable and relevant theory offered by a party 

affects the party's substantial rights). 

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We hold that the exclusion of the testimony of these expert 

witnesses was an abuse of discretion and error. Since those 

rulings led to the directed verdict and the judgment for the 

defendants, that judgment must be REVERSED and the case must be 

REMANDED for a new trial. 

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