Rebekah Hillman , individually v. the Toro Company

In the
United States Court of Appeals
For the Seventh Circuit
____________________
No. 24-2865
R EBEKAH HILLMAN , individually and as next friend of P.J.H.,
a minor, and JENNIFER HILLMAN ,
Plaintiffs-Appellants,
v.
THE TORO C OMPANY ,
Defendant-Appellee.
____________________
Appeal from the United States District Court for the
Central District of Illinois.
No. 4:21-cv-04081-SLD-JEH — Sara Darrow, Chief Judge.
____________________
A RGUED S EPTEMBER 11, 2025 — DECIDED J ANUARY 21, 2026
____________________
Before EASTERBROOK, HAMILTON , and M ALDONADO,
Circuit Judges.
HAMILTON , Circuit Judge. Rebekah Hillman lost her left leg
below the knee in a riding lawnmower accident. Rebekah, her
wife Jennifer Hillman, and their minor daughter P.J.H. sued
the manufacturer of the mower, The Toro Company, alleging
that the mower’s design was defective in several ways. Ac-
cording to the Hillmans, the mower should have had a

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2 No. 24-2865
mechanical brake independent of the hydrostatic transmis-
sion or an interlock ignition system, either of which would
have prevented the accident, and/or a rollover protection sys-
tem for rider safety in the event of a crash.
The district court excluded all of the Hillmans’ expert
evidence as unreliable or irrelevant and therefore granted
Toro summary judgment. The Hillmans have appealed,
focusing on the exclusion of the expert testimony they offered.
We affirm most of the district court’s evidentiary rulings, but
the district court did not directly address one expert’s
independent brake opinions. Those opinions are reliable and
relevant, and the expert’s qualifications are unchallenged.
Those opinions raise genuine disputes of material facts on the
independent brake theory. We therefore reverse the summary
judgment for Toro on the strict products liability and
negligent design theories based on the lack of an independent
brake. We affirm in all other respects and remand for trial.
I. Factual and Procedural Background
A. Zero-Radius-Turn Mowers
We relate the facts in the light most favorable to the Hill-
mans as the non-moving parties. E.g., Malen v. MTD Products,
Inc., 628 F.3d 296, 303 (7th Cir. 2010). Zero-radius-turn mow-
ers owe their distinctive maneuverability to the fact that the
rear wheels operate independently of each other. That design
allows the driver to pivot on a dime by manipulating separate
control levers on each side of the mower. Each rear wheel is
powered by a hydrostatic motor, which also provides the pri-
mary braking for the mower when the control levers are
pulled to the center.

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No. 24-2865 3
Defendant Toro manufactures a zero-radius-turn mower
called the Toro ZRT Timecutter 5000. In 2014, the Hillmans
purchased a Timecutter that had been designed and manufac-
tured in 2013. In addition to the primary hydrostatic braking
capacity, the Timecutter has an electric parking brake. The
parking brake is designed to keep the mower stationary, in-
cluding when stopped on an incline, but the parking brake is
not strong enough to stop the mower when it is already in
motion. The hydrostatic motors can be disengaged—thus dis-
abling all hydrostatic braking capacity—when the operator
inserts “bypass pins.” Doing so essentially puts the rear
wheels in neutral, which allows the mower to be pushed or
towed, for example.
At the center of this appeal, the Hillmans’ Timecutter did
not have an independent brake that could stop the mower
without relying on the hydrostatic motors. So if the mower
began to move while the bypass pins were pushed in, it would
have no brake strong enough to stop it. The Timecutter also
lacked a rollover protection system, meaning a roll bar and
seatbelt designed to keep the rider safe in the event of a rollo-
ver crash. The mower also lacked a safety interlock system
that would have prevented the operator from starting the en-
gine when the bypass pins were engaged and the hydrostatic
braking was thus disabled.
B. The Accident
In June 2020, Rebekah Hillman was using her Timecutter
to mow the Hillmans’ lawn. The mower became stuck in a
flower bed in the backyard. The backyard sloped gradually
down from a treeline toward the house. The flower bed close
to the house was much steeper. At the edge of the flower bed

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4 No. 24-2865
closest to the house, a retaining wall formed a sharp six-foot
drop onto a gravel bed.1
Jennifer came to help with the stuck mower. She disen-
gaged the mower’s rear wheels by pushing in the bypass pins
so she could tow it back up the incline. After she had towed
it, however, she did not pull the bypass pins back out. Re-
bekah got back on, started the engine, and pulled the motion
control levers to resume mowing. This action did not engage
the rear wheels because the bypass pins were still pushed in,
but it did disengage the parking brake. The mower began roll-
ing down the incline. Rebekah tried to use the levers to engage
the electric parking brake, to no avail. The mower gained
speed, gradually at first and then more quickly once it
reached the steeper flower bed. At that point, Rebekah tried
to jump clear of the mower onto the gravel below the retain-
ing wall. She was unable to jump clear, and the mower landed
on her legs. The fall and the impact of the mower striking her
while she lay on the ground fractured her right knee and the
bones in her left leg, which had to be amputated below the
knee.
C. This Lawsuit
The Hillmans are citizens of Illinois, and Toro is a Dela-
ware corporation with its principal place of business in Min-
nesota. The Hillmans sued in federal court in Illinois under
diversity jurisdiction. 28 U.S.C. § 1332. The Hillmans sought
damages for Rebekah’s injuries and resulting injuries to
1 We refer to the Hillmans by their first names to avoid confusion. The
district court’s opinion helpfully includes photographs that show the
slopes at the time of the accident. Hillman v. Toro Co., 2024 WL 4353032, at
*4 (C.D. Ill. Sept. 30, 2024).

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No. 24-2865 5
Jennifer and their daughter. The operative complaint raised
theories of strict products liability, negligent design, negligent
failure to warn, and breach of warranty. After discovery and
exchanges of expert witness reports, Toro moved for sum-
mary judgment on all theories and to exclude the Hillmans’
three expert witnesses. The Hillmans voluntarily dismissed
the breach of warranty theory but opposed summary judg-
ment on all other theories.
The district court granted Toro summary judgment on all
remaining theories, first excluding all of the Hillmans’ expert
reports in their entirety as unreliable or irrelevant. The court
then held that the strict products liability and negligent de-
sign theories failed as a matter of law without supporting ex-
pert evidence. The court also granted Toro summary judg-
ment on the failure-to-warn theories. Hillman v. Toro Co., 2024
WL 4353032 (C.D. Ill. Sept. 30, 2024).
II. Illinois Products Liability Law and Expert Evidence
Illinois law governs this diversity action. To prevail on
their strict products liability claims, the Hillmans must prove
that a condition of the Timecutter attributable to Toro made it
unreasonably dangerous at the time it left Toro’s control and
that the condition was a factual and proximate cause of Re-
bekah’s (and thus Jennifer’s and P.J.H.’s) injuries. Mikolajczyk
v. Ford Motor Co., 231 Ill. 2d 516, 525–27, 901 N.E.2d 329, 335–
36 (2008). Illinois recognizes three theories of strict products
liability: manufacturing defects, design defects, and failures
to warn. Id. at 548, 901 N.E.2d at 348.
Plaintiffs in a design defect case may use either or both of
two methods of proof to show that the defect makes a product
unreasonably dangerous. First, the consumer expectations

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6 No. 24-2865
test asks “whether the product is unsafe when put to a use
that is reasonably foreseeable considering its nature and func-
tion.” Id. at 554, 901 N.E.2d at 352. Second, the risk-utility test
asks whether “on balance the benefits of the challenged de-
sign outweigh the risk of danger inherent in such designs.” Id.
at 526–27, 901 N.E.2d at 336, quoting Lamkin v. Towner, 138 Ill.
2d 510, 529, 563 N.E.2d 449, 457 (1990). Under the risk-utility
test, “a plaintiff may prove a design defect by presenting evi-
dence of ‘the availability and feasibility of alternate designs at
the time of its manufacture’” or non-compliance with design
standards set by the industry, an authoritative voluntary as-
sociation, or government regulations. Calles v. Scripto-Tokai
Corp., 224 Ill. 2d 247, 263–64, 864 N.E.2d 249, 260 (2007), quot-
ing Anderson v. Hyster Co., 74 Ill. 2d 364, 368, 385 N.E.2d 690,
692 (1979).
To prevail on their negligence theories, the Hillmans must
prove that Toro breached a duty of care to them and that the
breach was a proximate cause of their injuries. Calles, 224 Ill.
2d at 270, 864 N.E.2d at 263. “The key distinction between a
negligence claim and a strict liability claim lies in the concept
of fault. In a strict liability claim, the focus is on the condition
of the product. However, in a negligence claim, a defendant’s
fault is at issue in addition to the condition of the product.”
Id. at 270, 864 N.E.2d at 263–64 (citations omitted).
Illinois intermediate appellate courts require expert testi-
mony in design defect cases involving “specialized
knowledge or expertise outside the layman’s knowledge.”
Baltus v. Weaver Division of Kidde & Co., 199 Ill. App. 3d 821,
834, 557 N.E.2d 580, 588 (1990); Henry v. Panasonic Factory Au-
tomation Co., 396 Ill. App. 3d 321, 326, 917 N.E.2d 1086, 1091–
92 (2009) (same). We have no reason to expect the Illinois

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No. 24-2865 7
Supreme Court would disagree with this widely accepted
principle in product-liability law.
Rule 702 of the Federal Rules of Evidence governs the ad-
missibility of expert testimony in the federal courts, even in a
diversity case controlled by state substantive law. Stutzman v.
CRST, Inc., 997 F.2d 291, 295 (7th Cir. 1993); accord, Love v.
United States, 17 F.4th 753, 755–56 (7th Cir. 2021) (Rule 702
governed admission of expert evidence in federal tort claim
case governed by state substantive law). Rule 702 provides:
A witness who is qualified as an expert by
knowledge, skill, experience, training, or educa-
tion may testify in the form of an opinion or oth-
erwise if the proponent demonstrates to the
court that it is more likely than not that:
(a) the expert's scientific, technical, or other spe-
cialized knowledge will help the trier of fact to
understand the evidence or to determine a fact
in issue;
(b) the testimony is based on sufficient facts or
data;
(c) the testimony is the product of reliable prin-
ciples and methods; and
(d) the expert’s opinion reflects a reliable appli-
cation of the principles and methods to the facts
of the case.
The district court plays a crucial role as “evidentiary gate-
keeper,” admitting expert evidence only after evaluating:
“(1) the proffered expert’s qualifications; (2) the reliability of the
expert’s methodology; and (3) the relevance of the expert’s

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8 No. 24-2865
testimony.” Gopalratnam v. Hewlett-Packard Co., 877 F.3d 771,
778–79 (7th Cir. 2017), quoting Krik v. Exxon Mobil Corp., 870
F.3d 669, 674 (7th Cir. 2017), citing in turn Daubert v. Merrell
Dow Pharmaceuticals, Inc., 509 U.S. 579, 589 (1993). Our opin-
ions have identified long lists of potential factors for district
courts to consider in addressing reliability, but those factors,
we emphasize once again, are neither mandatory nor dispos-
itive. See id. at 779–80. “Rather, the law grants a district court
the same broad latitude when it decides how to determine re-
liability as it enjoys in respect to its ultimate reliability deter-
mination.” Kumho Tire Co., Ltd. v. Carmichael, 526 U.S. 137, 142
(1999). We apply an abuse of discretion standard of review
and “shall not disturb the district court’s findings unless they
are manifestly erroneous.” Anderson v. Raymond Corp., 61
F.4th 505, 508 (7th Cir. 2023), quoting Naeem v. McKesson Drug
Co., 444 F.3d 593, 607–08 (7th Cir. 2006).
To earn deference, however, the district court must show
its work. See Gayton v. McCoy, 593 F.3d 610, 616 (7th Cir. 2010).
We review de novo whether a district court has followed Rule
702’s framework for evaluating expert evidence. Anderson, 61
F.4th at 508. Announcing that a particular expert opinion
“simply does not pass the Daubert test” is “a conclusion—not
an analysis—to which we owe no deference.” Id. at 508–09.
Our threshold review is not exacting, but it is granular. Where
an expert report contains multiple opinions, deference is due
only for the district court’s decisions on the opinions it satis-
factorily addresses. See Gayton, 593 F.3d at 616–18 (separately
addressing three excluded opinions by same expert; affirming
exclusion of one but reversing on two others, including one
the district court did not address at all).

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No. 24-2865 9
III. Analysis
We find no reason to disturb most of the district court’s
exclusions of the Hillmans’ expert witnesses’ opinions. The
district court satisfactorily addressed the reports by Kelly
Kennett and David Bilek, and much of Thomas Berry’s report.
The court explained specifically why, in its view, most of the
opinions it excluded were unreliable, irrelevant, or both. See
Hillman v. Toro Co., 2024 WL 4353032. The court’s express
findings on relevance and reliability were not manifestly er-
roneous. The problem, however, is that the district court did
not address the portion of Berry’s report explaining the need
for an independent brake. We consider de novo the admissi-
bility of his opinion on that question. The opinion is relevant
and reliable, and Toro has not questioned Berry’s qualifica-
tions. He holds a master’s degree in mechanical engineering
and has been a licensed professional engineer for decades. We
conclude that his independent brake opinions are admissible
under Rule 702 and establish genuine disputes of material fact
that preclude summary judgment on the Hillmans’ strict
products liability and negligent design theories based on the
lack of an independent brake.2
A. Kelly Kennett
Kennett offered two opinions: (1) an independent brake
would have prevented the accident entirely; and (2) a rollover
protection system would have mitigated Rebekah’s injuries.
The district court excluded the first opinion as “too obvious.”
2 The Hillmans waived their failure-to-warn theory by choosing not
to address the district court’s reasoning. Bradley v. Village of University
Park, 59 F.4th 887, 897 (7th Cir. 2023). We thus do not address the portions
of the expert opinions related to that theory.

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10 No. 24-2865
The court excluded the second as unreliable because Kennett
had no testing data on how a rollover protection system per-
forms in a “forward pitch-over event.” The district court
noted as well that the second opinion was unhelpful because
Kennett opined on rollover protection systems generally and
not on any particular form. We find no error in this reason-
ing.3
B. David Bilek
Bilek offered three opinions: (1) an independent brake
would have prevented the accident entirely, and its absence
made the Timecutter defective and unreasonably dangerous;
(2) a safety interlock would have prevented the accident en-
tirely; and (3) the Timecutter was defective and unreasonably
dangerous without a rollover protection system. The district
court excluded the first because the causation opinion (like
Kennett’s) was too obvious and because he conducted no test-
ing on an independent brake. The court excluded the second
opinion on a safety interlock as too obvious and excluded the
third also because Bilek conducted no testing on how a rollo-
ver protection system would have prevented Rebekah’s inju-
ries. Though we might not necessarily agree with all of this
3 Kennett’s report also discussed the mechanism of Rebekah’s injury.
The district court did not separately address that section, and under An-
derson we cannot give deference based on its statement that “Kennett’s
opinions [in their entirety, presumably] do not pass muster under Daubert
and Federal Rule of Evidence 702 and cannot be used to oppose summary
judgment.” Anderson v. Raymond Corp., 61 F.4th 505, 508–09 (7th Cir. 2023).
To the extent the precise mechanism of Rebekah’s injury is relevant on
remand to the independent brake theory (which it may not be), we reverse
the exclusion of that portion of his report. See Gayton v. McCoy, 593 F.3d
610, 616 (7th Cir. 2010).

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No. 24-2865 11
analysis if we had to consider Bilek’s report in the first in-
stance—we explain below why portions of Berry’s report are
admissible even though he too conducted no testing—the def-
erential standard of review matters. We find no manifest er-
rors here either.4
C. Thomas Berry
Berry offered two opinions: (1) the Timecutter was
defective and unreasonably dangerous because it lacked an
independent service brake, which would have prevented the
4 Bilek’s report also offered an accident reconstruction, which the dis-
trict court provided no reason to doubt and even relied on in its own rec-
itation of the facts. To the extent that the accident reconstruction is rele-
vant to the independent brake claims—which it may be if Toro contests
whether Rebekah would have had the time and distance to use an inde-
pendent brake if one had been present—the Hillmans are entitled to rely
on that portion of Bilek’s report. See Gayton, 593 F.3d at 618.
As to Bilek’s third opinion, on the lack of a rollover protection system,
the district court also wrote: “Whether the Subject Mower is unreasonably
dangerous and therefore defective is a legal conclusion and again, ‘experts
may not testify as to legal conclusions that will determine the outcome of
the case.’” 2024 WL 4353032, at *14, quoting Marquis ProCap Sys. v. Novo-
zymes North America, Inc., No. 20-1020, 2023 WL 3775173, at *2 (C.D. Ill.
June 2, 2023) (Mihm, J.). That analysis was incorrect. The case on which
Marquis relied concerned expert testimony that was “largely on purely le-
gal matters,” namely whether the city’s actions violated a federal statute.
Good Shepherd Manor Foundation, Inc. v. City of Momence, 323 F.3d 557, 564
(7th Cir. 2003). Judges do not need expert testimony to interpret and apply
domestic statutes. See United States v. Caputo, 517 F.3d 935, 942 (7th Cir.
2008) (“The only legal expert in a federal courtroom is the judge.”).
Whether a product is unreasonably dangerous is not a purely legal ques-
tion. Also, the former rule that a witness cannot testify on an ultimate issue
no longer applies in federal civil cases. Fed. R. Evid. 704(a); Walker v. Soo
Line Railroad Co., 208 F.3d 581, 587 n.2 (7th Cir. 2000).

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12 No. 24-2865
accident entirely; and (2) the Timecutter was defective and
unreasonably dangerous because it lacked a rollover
protection system, which would have mitigated Rebekah’s
injuries. The district court excluded the second opinion
because Berry offered no testing data on rollover protection
systems in forward longitudinal rollovers, as opposed to
lateral or backward longitudinal rollovers, and so he failed to
“apply his expertise to the specific facts of this case.” The
district court concluded that “Berry’s opinions do not satisfy
the reliability standards of Daubert and Federal Rule of
Evidence 702” and excluded them. We find no manifest errors
in the district court’s analysis of Berry’s opinions on the
rollover protection system.5
Absent from the district court’s discussion of Berry’s re-
port, however, is any analysis of his opinion on the lack of an
independent brake. The conclusory statement that his opin-
ions “do not satisfy the reliability standards of Daubert and
[Rule 702]” is not enough to warrant deference. Anderson, 61
F.4th at 508–09. So we consider de novo the admissibility of
Berry’s opinions on the lack of an independent brake.
1. Berry’s Independent Brake Opinions Pass Muster
Berry’s opinions on an independent brake are admissible
under Rule 702 because they are both relevant and reliable.
Berry’s opinions are relevant both to the risk-utility test that
governs the strict liability theory and to whether Toro
breached its duty of care to the Hillmans in designing the
5 Berry also opined on the lack of an ignition safety interlock, which
the district court did not mention at all, but as with the failure-to-warn
theories, the Hillmans have waived it by not pursuing that point on ap-
peal. See Bradley, 59 F.4th at 897.

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No. 24-2865 13
Timecutter, part of the negligent design theory. Specifically,
Berry opined that the Timecutter’s lack of an independent
brake made it “defective in design and unreasonably danger-
ous,” and also that Toro “knew or should have known of tech-
nically and economically feasible design alternatives that
would have significantly reduced the risk without adversely
affecting the utility of the machine.” Berry identified several
such alternatives. He reported that at least one other zero-ra-
dius-turn mower manufactured by Toro had an independent
brake. He also reported that Hydro-Gear, the company that
made the hydrostatic motor used in the Timecutter, “had
available a disc brake design that could have been utilized.”
Berry also identified two other zero-radius-turn mowers with
independent brakes. One was a John Deere model with a
“simple park brake” that “uses a lever to rotate two steel
pawls against the rear tires” and withstands slopes of up to
30 degrees—greater than three times the slope of the Hill-
mans’ lawn, at 9.5 degrees. He also identified a “more sophis-
ticated brake system … such as that provided by Scag on its
Patriot and Freedom Z mower,” the latter being “only slightly
bigger than the Toro Timecutter.”
As for reliability, Berry cited several industry publications
and patents to support and explain the need for an independ-
ent brake. He quoted a report given to the American Society
of Agricultural Engineers as follows:
For descending slopes, the hydrostatic trans-
mission will provide some braking torque to the
wheels due to the retarding characteristic of the
engine. This is a transmission characteristic
called “dynamic braking”. This braking capability
does not eliminate the need for a service brake. Some

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14 No. 24-2865
type of service brake must be included in the ve-
hicle design to aid dynamic braking or for use
in case of transmission failure. Hydrostatic brak-
ing must not be considered as the primary braking
device for vehicles at static conditions either with the
engine running or the engine off….
(Emphasis added.) Berry also quoted a Hydro-Gear patent
stating that a “completely open hydraulic circuit”—as the
Timecutter was once Jennifer pushed in the bypass pins—
“can lead to uncontrolled free-wheeling of the vehicle and cre-
ate significant safety risks.”
Berry also quoted a report from the Fluid Power Safety
Institute explaining a point that may be particularly
important here because of the human error of failing to pull
out the bypass pins. The report explained that operator error
is not the only scenario for which an independent brake is
essential. The report explained that a loss of hydrostatic
braking capacity could be caused in several ways, including
unexpected loss of a transmission line due to wear, wear in
the motor, valve failure, and loss of oil in the reservoir. As the
Institute put it: “There are simply too many things that can go
wrong.”
Toro has not offered a sound reason to exclude Berry’s in-
dependent brake opinions as irrelevant or unreliable. Toro
points out correctly that Berry never tested his alternative de-
signs with independent brakes. And of course, testing of al-
ternative designs can be an important factor in evaluating the
reliability of proposed expert testimony. Winters v. Fru-Con
Inc., 498 F.3d 734, 742–43 (7th Cir. 2007), quoting Dhillon v.
Crown Controls Corp., 269 F.3d 865, 870 (7th Cir. 2001). While
“hands-on testing” can help support an expert opinion, it is

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No. 24-2865 15
not always “an absolute prerequisite” for admission. Cum-
mins v. Lyle Industries, 93 F.3d 362, 369 (7th Cir. 1996); see also
Baley v. Federal Signal Corp., 2012 IL App (1st) 093312, ¶ 81, 982
N.E.2d 776, 796 (2012) (same under Illinois law).
Berry did not dream up new and untested designs. He
relied instead on products that were on the market at the
relevant time, including other zero-radius-turn mowers
offered by Toro itself, as well as components offered by the
manufacturer of the hydrostatic motor that Toro used in the
Timecutter. He also relied on zero-radius-turn mowers
offered by other companies that included independent
brakes. Berry’s alternative designs were taken from
comparable products actually on the market. We can
reasonably infer that those mowers with independent brakes
were commercially and technically practical. We see no
reason to treat Berry’s alternative designs as based on
speculation that required him to carry out tests before he
could offer his opinion in court. Moreover, recall that the
district court excluded Kennett’s and Bilek’s opinions on
causation as so obvious as not to be helpful. Such an obvious
point did not require experimental confirmation under these
circumstances.
2. Genuine Disputes of Material Facts
Toro offers other arguments on the independent brake
theory. They are not objections to the admissibility of Berry’s
expert testimony but instead alternative reasons to affirm
summary judgment on the independent brake theory. The
district court did not reach these other arguments, but they do
not persuade us to affirm on alternate grounds.

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16 No. 24-2865
First, Toro argues that the primary cause of Rebekah’s
injuries was Jennifer’s failure to pull out the bypass pins, not
a failure of the hydrostatic system. In its motion for summary
judgment, Toro labeled this contention as a proximate cause
issue, arguing that the omission of an independent brake
“merely furnished the condition … by which Rebekah’s
injury was made possible” through Rebekah’s and Jennifer’s
own “independent acts.” However, because the Hillmans are
the plaintiffs in this case, not third parties (nor third-party
defendants), that argument is better treated as getting to
comparative fault. See Abrams v. City of Chicago, 211 Ill. 2d 251,
259, 811 N.E.2d 670, 675 (2004) (“If the negligence charged
does nothing more than furnish a condition by the which the
injury is made possible, and that condition causes an injury
by the subsequent, independent act of a third person, the
creation of the condition is not the proximate cause of the
injury.” (emphasis added)); see also Walker v. Macy’s
Merchandising Group, Inc., 288 F. Supp. 3d 840, 857 (N.D. Ill.
2017) (applying Abrams to case involving burn victim’s suit
against two distinct clothing manufacturers). Illinois follows
a modified comparative fault regime for both negligent
design and strict products liability theories. 735 Ill. Comp.
Stat. 5/2-1116 (2025). A genuine dispute exists as to whether
Rebekah or Jennifer acted negligently at all, and if so, whether
they were more than fifty percent at fault for the accident.
Here, arguments about comparative fault are appropriate for
a jury but not a foundation for summary judgment.
Second, Toro argues factual causation, pointing out that
the Hillmans’ experts conducted no tests establishing that an
independent brake would have prevented the accident. This
argument is odd, and certainly not persuasive, given the dis-
trict court’s exclusion of Kennett’s and Bilek’s causation

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No. 24-2865 17
opinions on the lack of an independent brake as “too obvi-
ous.” Berry’s report said that the “simple” independent brake
on one of John Deere’s zero-radius-turn mowers is effective at
slopes of up to 30 degrees, over three times as steep as the
slope of the Hillmans’ yard. A jury could infer from the fact
that Rebekah had enough time to try to engage the electric
parking brake that she could have tried to engage an inde-
pendent brake instead, or as well. Perhaps Toro may be able
to offer evidence that an independent brake would not have
stopped the mower or slowed it enough to mitigate Rebekah’s
injuries, or that Rebekah would have had neither the time nor
the wherewithal to use one. We cannot say, however, that
there is no genuine dispute of fact on factual causation.
Third, Toro argues that Jennifer’s failure to disengage the
bypass pins distinguishes this accident from every other loss-
of-control incident involving the Timecutter going back to at
least 2005, the time limit for discovery in this case. Toro sug-
gests the apparent uniqueness of this accident means no jury
could find the benefits of adding an independent brake out-
weighed the costs of doing so. But an independent brake
would allow the Timecutter to stop when it loses hydrostatic
braking capacity for any reason, not just an operator’s error in
failing to reset the bypass pins. “There are simply too many
things that can go wrong,” as the Fluid Power Safety Institute
warned. The record of loss-of-control incidents involving the
Timecutter since 2005 supports that claim. Neither party has
quantified the cost per machine. Berry described the needed
system as “simple” and one that was available in other prod-
ucts on the market at the relevant time. An expert witness for
Toro countered that adding an independent brake would be
“adding unnecessary cost,” but he did not specify that cost.

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18 No. 24-2865
On this record, the cost-justification of an independent brake
remains in genuine dispute.
Finally, Toro argues that the Timecutter’s hydrostatic
braking system complies with the applicable standard for
zero-radius-turn mowers set by the American National Stand-
ards Institute, the “central organization that develops and ac-
credits industry standards” for products in the United States.
Lemmermann v. Blue Cross Blue Shield of Wisconsin, 713 F. Supp.
2d 791, 801 (E.D. Wis. 2010). Under Illinois tort law, compli-
ance with industry standards is a “factor to be considered in
the balance” in a negligent design case, not an automatic de-
fense to liability. Jablonski v. Ford Motor Co., 2011 IL 110096,
¶ 91, 955 N.E.2d 1138, 1156 (2011). Toro may make this point
to a jury, but it does not establish the absence of a genuine
dispute of material fact as to whether the lack of an independ-
ent brake was a defect.
We REVERSE judgment for Toro to the extent it was based
on rejection of the Hillmans’ independent brake theory. The
case is REMANDED for further proceedings consistent with
this opinion.

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