AI Case Brief
Generate an AI-powered case brief with:
đKey Facts
âïžLegal Issues
đCourt Holding
đĄReasoning
đŻSignificance
Estimated cost: $0.10â$0.50 per brief, depending on opinion length and retries
Full Opinion
[[COURTLISTENER_SUBOPINION {"id":"11211283","type":"100trialcourt","part":"other","author":null,"source_field":"html_with_citations"}]]
1
2
3
4
5
UNITED STATES DISTRICT COURT
6 WESTERN DISTRICT OF WASHINGTON
AT SEATTLE
7
MATTHEW HARTLEY, CASE NO. 24-cv-01078-JHC
8
Plaintiff, ORDER
9
v.
10
SUNBELT RENTALS, INC. ET AL.,
11
Defendants.
12
13
14
I
15 INTRODUCTION
16 This matter comes before the Court on Defendant Custom Equipment LLCâs Motion to
17 Exclude Testimony of Plaintiffâs Expert Craig Sylvester (Dkt. # 41) and Plaintiffâs Subjoined
18 Motion to Strike the Declaration of Mac Abfall (Dkt. # 52). The Court has considered the
19 materials filed in support of and in opposition to the motions, pertinent portions of the record,
20 and the applicable law. Being fully advised, the Court: (1) DENIES Defendantâs Motion to
21 Exclude; (2) and GRANTS in part and DENIES in part Plaintiffâs Motion to Strike.
22
23
24
1 II
BACKGROUND
2
Plaintiff Matthew Hartley sues Defendants Sunbelt Rental Inc. and Custom Equipment
3
LLC to recover for personal injuries he sustained during a jobsite incident on June 14, 2021.
4
Dkt. # 1-1 at 5. Plaintiff alleges that on June 14, 2021, he âattempted to move a Sunbelt Rentals
5
Hy-Brid Lift HB-1030 down a ramp when suddenly and without warning it began to rapidly roll
6
down the slope of the ramp despite no effort on [his] part to power the lift forward.â Id. at 6. He
7
further alleges that the lift, which was manufactured by Custom Equipment, LLC, ârolled
8
uncontrollably into a concrete wall at a rapid rate of speed[,]â causing âdebilitating physical
9
injuriesâ and a variety of economic and noneconomic harms. Id. Plaintiff argues that
10
Defendants are liable under a negligence and/or strict liability theory, as his damages are
11
allegedly the âdirect and proximate result of [Defendantsâ] negligence and the unsafe condition
12
of the lift[.]â Id. at 7â8.
13
Plaintiff retained Craig Sylvester, a forensic engineering expert, to determine the âroot
14
causeâ of the accident. Dkt. # 53 at 2; see also Dkt. # 41 at 2. According to Mr. Sylvester, âthe
15
root cause of the incident [on] June 14, 2021 was a mis-wired emergency stop button, as well as
16
the placement of one or both of the parking brake levers at the rear of the machine in an
17
intermediate position[.]â Dkt. # 53 at 2. Mr. Sylvester contends that he reached this conclusion
18
âbased on [his] review of file materialsâ as well as his âown investigation, analysis and testingâ
19
of the lift. Id. He further notes that his âengineering opinion regarding the root cause of the
20
incident . . . was based on seven (7) sources of information[,]â which included eye-witness
21
deposition testimony from Plaintiff and his spotter, Arturo Caleb Zertuche, three hands-on
22
inspections of the lift, his own engineering analysis of the liftâs braking design, and the BNB
23
incident investigation results provided by Defendants. Id. at 3.
24
1 Mr. Sylvesterâs opinions about the root cause of the incident were included in his expert
2 disclosure report, dated August 11, 2025, and shared during his deposition on September 10,
3 2025. See Dkt. ## 53 at 6; see also Dkt. # 41 at 3â4. Mr. Sylvester maintains that after
4 completing his initial expert disclosure report and being deposed by defense counsel, certain
5 âconfusionâ and âinconsistenciesâ remained. See Dkt. # 53 at 7â8. Accordingly, Mr. Sylvester
6 continued his investigation and obtained more information on the lift at issue. Id. at 8. He then
7 wrote a supplemental report, dated September 26, 2025, âto reflect the new information [he]
8 received[.]â Id. at 9.
9 After Mr. Sylvesterâs supplemental report was submitted, Defendant Custom Equipment
10 moved to âstrike certain expert opinions and limit testimony of disclosed expert Craig
11 Sylvester.â Dkt. # 41 at 1. The same day, Defendant also moved for summary judgment against
12 Plaintiff, see Dkt. # 39, and filed the âDeclaration of Mac Abfall in Support of Motion for
13 Summary Judgment and Motion to Exclude or Limit Testimony of Craig Sylvester.â Dkt. # 44.
14 Plaintiff responded, asking the Court to deny Defendantâs Motion to Exclude and strike the
15 Declaration of Mac Abfall, at least in part. See Dkt. # 52 at 2.
16 III
DISCUSSION
17
A. Defendantâs Motion to Exclude
18
Defendant requests the Court âexclude the portions of Mr. Sylvesterâs opinions that are
19
untimely, speculative and unhelpful to the jury.â Dkt. # 41 at 11. Defendant argues that
20
exclusion is warranted because Mr. Sylvesterâs: (1) supplemental opinions on electromagnetic
21
braking assistance, back emf braking assistance, and arc suppression circuits are untimely and
22
unhelpful to the jury; (2) opinions on the intermediate position of the brake levers are
23
speculative; (3) opinions on the parking brakeâs holding torque are unhelpful to the jury; and (4)
24
1 opinions that the pre-start inspection checklist failed to adhere to the ANSI A92.22 standards are
2 unhelpful to the jury. Dkt. # 41 at 5â6. Plaintiff responds that: (1) Defendantâs challenges to the
3 supplemental opinions are moot, as âMr. Sylvester has no intention of testifying that the HB
4 1030 should have included âelectromagnetic,â âback emfâ or an âarc suppression circuitâ at the
5 time of trialâ; (2) Mr. Sylvesterâs opinions on the intermediate position of the brake levers are
6 âsupported by substantial evidenceâ and ânot speculativeâ; (3) Defendantâs challenge to the
7 holding torque opinion is moot, as Mr. Sylvester âwill not be testifying regarding [the document
8 that references holding torque]â; and (4) Defendantâs challenge to the ANSI A92.22 standards
9 opinion is moot, as Plaintiff concedes that such standards would not apply to the lift at issue and
10 âupon withdrawal of such opinion, nothing should exclude Mr. Sylvester from testifying that
11 industry standards would include a pre-start inspection of the braking system as a matter of
12 common sense and industry standards.â Dkt. # 52 at 4â6, 9. As discussed below, the Court
13 agrees with Plaintiff and thus denies Defendantâs Motion to Exclude.
14 Plaintiff contends, and Defendant accepts, that âMr. Sylvester has no intention of
15 testifying that the HB 1030 should have included âelectromagnetic,â âback emfâ or an âarc
16 suppression circuitâ at the time of trial.â Dkt. ## 52 at 5; 63 at 3. The Court thus finds these
17 admissibility questions to be moot. Plaintiff also states that Mr. Sylvester âwill not be testifying
18 regarding [the holding torque] documentâ and that the â[ANSI A92.22] standards, which were
19 adopted after the manufacture and sale of the HB 1030, would not apply to [the unit at issue.]â
20 Dkt. # 52 at 6, 9. As Defendant does not challenge the admissibility of testimony by Mr.
21 Sylvester that âindustry standards would include a pre-start inspection of the braking system as a
22 matter of common sense and industry standardsâ nor do they otherwise challenge Plaintiffâs
23 concessions on these issues, see generally Dkt. ## 41; 63, the Court likewise finds these
24
1 admissibility questions moot. Accordingly, the Court denies as moot Defendantâs Motion to
2 Exclude these opinions.
3 As for Mr. Sylvesterâs opinions on the intermediate position of the brake levers, the Court
4 does not find exclusion proper under the applicable legal standards. Under Federal Rule of
5 Evidence 702, an expert witness âmay testify in the form of an opinion or otherwiseâ provided:
6 (a) the expertâs scientific, technical, or other specialized knowledge will help the
trier of fact to understand the evidence or to determine a fact in issue;
7
(b) the testimony is based on sufficient facts or data;
8
(c) the testimony is the product of reliable principles and methods; and
9
(d) the expertâs opinion reflects a reliable application of the principles and methods
10 to the facts of the case.
Fed. R. Evid. 702. In other words, Rule 702 âtasks a district judge with âensuring that an
11
expertâs testimony both rests on a reliable foundation and is relevant to the task at hand.ââ Hyer
12
v. City & Cnty. of Honolulu,
118 F.4th 1044, 1055
(9th Cir. 2024) (quoting Elosu v. Middlefork
13
Ranch Inc.,
26 F.4th 1017, 1024
(9th Cir. 2022)). But in performing this role, a district court
14
serves as âa gatekeeper, not a fact finder.â Elosu,
26 F.4th at 1020
(quoting Primiano v. Cook,
15
598 F.3d 558
, 568 (9th Cir. 2010)). It thus âmay screen an expert opinion for reliability, and
16
may reject testimony that is wholly speculative,â but cannot âweigh the expertâs conclusions or
17
assume a factfinding role.â Id.
18
A district court has âbroad discretionâ in making relevancy and reliability rulings. Hyer,
19
118 F.4th at 1055
(citing City of Pomona v. SQM N. Am. Corp.,
866 F.3d 1060, 1065
(9th Cir.
20
2017)). For relevancy, the âbar is low,â see Messick v. Novartis Pharms. Corp.,
747 F.3d 1193
,
21
1196 (9th Cir. 2014), with courts finding expert testimony relevant so long as it âwill assist the
22
trier of fact to understand the evidence or to determine a fact in issue.â Daubert v. Merrell Dow
23
Pharms., Inc. (âDaubert Iâ),
509 U.S. 579, 589
(1993) (citing Fed. R. Evid. 702(a)). For
24
1 reliability, courts often consider: â1) whether a theory or technique can be tested; 2) whether it
2 has been subjected to peer review and publication; 3) the known or potential error rate of the
3 theory or technique; and 4) whether the theory or technique enjoys general acceptance within the
4 relevant scientific community.â United States v. Hankey,
203 F.3d 1160, 1167
(9th Cir. 2000)
5 (citing Daubert I, 509 U.S. at 592â94). But these factors are not exhaustive nor intended to be
6 applied in every case.
Id.
(citing Kumho Tire Co. v. Carmichael,
526 U.S. 137, 150
(1999)).
7 Rather, courts have âbroad latitude in determining whether an expertâs testimony is reliableâ and
8 âin deciding how to determine the testimonyâs reliability.â Hangarter v. Provident Life &
9 Accident Ins. Co.,
373 F.3d 998, 1017
(9th Cir. 2004) (internal quotations omitted).
10 The Court concludes that Mr. Sylvesterâs opinions on the intermediate position of the
11 brake levers âboth rests on a reliable foundation and is relevant to the task at hand.â Hyer, 118
12 F.4th at 1055. As for relevancy, the Court finds that Mr. Sylvesterâs opinions on the
13 intermediate position of the brake levers will âassist the trier of factâ to determine the root cause
14 of the June 14, 2021 incident. As the root cause of the incident is âa fact in issue,â Mr.
15 Sylvesterâs testimony satisfies the standard for relevancy. As for reliability, the Court concludes
16 that Mr. Sylvester reviewed numerous sources of information, utilized reliable principles and
17 methods of forensic engineering, and reliably applied said principles and methods to the facts of
18 the case. Although Defendant challenges Mr. Sylvesterâs opinions for being improperly based
19 on the BNB incident investigation results, i.e., ânotes for an unknown purpose and by an
20 unknown author,â see Dkt. # 41 at 9, the Court notes that Mr. Sylvesterâs investigation was not
21 limited to this document. See Dkt. # 53 at 3â4. Rather, Mr. Sylvester âconsidered seven
22 categories of evidence in reaching his conclusion, only one of which was a document generated
23 during the course of BN Builders investigation, which occurred shortly after the incident in
24
1 question.â Dkt. # 52 at 4. The Court thus declines to exclude Mr. Sylvesterâs testimony on the
2 brake levers as âspeculative.â
3 The Court also notes that while Defendant raises various other arguments for exclusion in
4 their Motion and Reply, none of these arguments provide a proper basis for exclusion, as they all
5 speak to issues of fact-finding, not gatekeeping. For example, Defendant argues that Mr.
6 Sylvesterâs brake lever opinion is improper because it âleaves the jury to speculate that the brake
7 levers were in [an intermediate] configuration at the time of the incident.â Dkt. # 41 at 10.
8 While this may be true, it does not provide a valid basis for the Court to exclude the testimony at
9 this stageâit merely creates a potential factual dispute for the trier of fact to resolve at trial.
10 Similarly, Defendantâs disagreement with Mr. Sylvesterâs exclusion of other possible
11 explanations for the accident and his reasons for doing so do not render his opinions
12 inadmissibleâthey merely make it more likely that the trier of fact will view Mr. Sylvesterâs
13 conclusions about the root cause of the accident less credible. Because the Court must act as âa
14 gatekeeper, not a fact finder,â see Elosu,
26 F.4th at 1020
, it cannot exclude portions of Mr.
15 Sylvesterâs testimony for any of these fact-finding based reasons.
16 Accordingly, the Court DENIES Defendantâs Motion to Exclude.
17 B. Plaintiffâs Motion to Strike
18 Plaintiff asks the Court to strike the Declaration of Mac Abfall (Dkt. # 44), particularly
19 with respect to paragraphs 9 through 16. Dkt. # 52 at 2â3. Plaintiff contends that the
20 Declaration must be stricken because âMr. Abfall strays from his role as a fact witness, to that of
21 an expertâ and improperly provides âârebuttalâ opinions to that of Mr. Sylvester.â
Id.
at 2â3.
22 Defendant rejects Plaintiffâs characterization of the Declaration as âundisclosed expert
23 testimony[,]â arguing that Mr. Abfall does not offer âexpert opinionsâ but merely âgeneric
24 background [information] on how the scissor lift functionsâ that is rooted in his personal
1 knowledge. Dkt. # 63 at 2. The Court agrees with both parties in part and thus grants in part and
2 denies in part Plaintiffâs Motion to Strike.
3 Under the Federal Rules of Evidence, â[i]f a witness renders an opinion as a lay witness,
4 that opinion must comply with [Rule] 701, which limits lay witnessâ testimony to âthose opinions
5 or inferences which are (a) rationally based on the perception of the witness, (b) helpful to a clear
6 understanding of the witnessâ testimony or the determination of a fact in issue, and (c) not based
7 on scientific, technical or other specialized knowledge within the scope of Rule 702.ââ
8 Gershkowitz v. State Farm Gen. Ins. Co.,
2022 WL 17251978
, at *2 (C.D. Cal. Aug. 26, 2022)
9 (quoting Fed. R. Evid. 701). âThus, under Rule 701, any part of a witnessâ testimony that is
10 based upon scientific, technical, or other specialized knowledge within the scope of Rule 702 is
11 governed by the standards of Rule 702 and the corresponding disclosure requirements of the
12 Federal Rules of Civil Procedure.â
Id.
This includes testimony by a lay witness that directly or
13 indirectly âintimatesâ causation of an accident based on the witnessâs technical knowledge. See
14 id. at *3 (collecting cases). But does not include general testimony by a lay witness based on
15 their personal knowledge, âeven if the subject matter [of the testimony] is specialized or
16 technical.â See United States v. Losch,
603 F. Supp. 3d 795
, 798 (D. Ariz. 2022) (internal
17 quotation marks and citations omitted).
18 Here, both parties agree that Mr. Abfall is not an expert witness and that his Declaration
19 is not an expert opinion. See Dkt. ## 41 at 2; 63 at 1. Accordingly, âany testimonyâ by Mr.
20 Abfall that âfall[s] within Rule 702, rather than Rule 701, must be excluded.â Gershkowitz, 2022
21 WL 17251978
, at *2. As the Court finds that Mr. Abfall is a lay witness with personal
22 knowledge regarding the functions and technical specifications of the HB 1030 lift, it finds that
23 his general testimony about the lift is proper. Because Plaintiff does not challenge Mr. Abfallâs
24
1 personal knowledge nor the helpfulness of his testimony, see generally Dkt. # 52, the Court finds
2 no basis to strike the Declaration in full or in part as to paragraphs 9-13 and 15.
3 As for paragraphs 14 and 16, the Court finds exclusion warranted. Unlike the rest of the
4 Declaration, these paragraphs specifically reference and respond to Mr. Sylvesterâs expert
5 opinions. Paragraph 14 states that âeven if the parking brake was circumvented in such a way
6 [as described by Mr. Sylvester], this would not reduce or eliminate the dynamic braking that
7 exists for the equipmentâ and paragraph 16 claims that, contrary to Mr. Sylvesterâs opinion, there
8 is no âdiscrepancyâ between the cited document and the lift at issue. Dkt. # 44 at 4â5. While
9 Defendant is correct that none of these statements directly opine âon causation, damages, or
10 product defect,â the Court does find that these paragraphs âintimateâ that both the intermediate
11 position of the brake lever and the liftâs divergence from the document did not cause the
12 accident. As a result, the Court finds it proper to strike paragraphs 14 and 16, as the testimony in
13 these paragraphs falls within the scope of Rule 702 and Defendant has not satisfied Rule 702âs
14 requirements for this testimony.
15 Accordingly, the Court GRANTS in part and DENIES in part Plaintiffâs Motion to
16 Strike.
17 IV
CONCLUSION
18
For these reasons,
19
(a) The Court DENIES Defendantâs Motion to Exclude (Dkt. # 41);
20
(b) The Court GRANTS in part and DENIES in part Plaintiffâs Motion to Strike (Dkt.
21
# 52). Paragraphs 14 and 16 of the Declaration of Mac Abfall (Dkt. # 44) are
22
hereby stricken.
23
//
24
1 Dated this 24th day of November, 2025.
Cok. Chu
3 John H. Chun
United States District Judge
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24Case Information
- Court
- W.D. Wash.
- Decision Date
- November 24, 2025
- Status
- Precedential