1

Filed 2/14/14 Corbo v. Taylor-Dunn Mfg. Co. CA1/2

NOT TO BE PUBLISHED IN OFFICIAL REPORTS

California Rules of Court, rule 8.1115(a), prohibits courts and parties from citing or relying on opinions not certified for 

publication or ordered published, except as specified by rule 8.1115(b). This opinion has not been certified for publication

or ordered published for purposes of rule 8.1115. 

IN THE COURT OF APPEAL OF THE STATE OF CALIFORNIA

FIRST APPELLATE DISTRICT

DIVISION TWO

CHRISTOPHER CORBO et al.,

Plaintiffs and Appellants,

v.

TAYLOR-DUNN MANUFACTURING 

COMPANY,

Defendant and Respondent.

 A135393

 (Alameda County

 Super. Ct. No. HG09477272)

I. INTRODUCTION

Christopher Corbo was injured when his foot was crushed by an electric flatbed 

truck manufactured by Taylor-Dunn Manufacturing Company. A jury found that TaylorDunn was liable for damages incurred by Corbo and his wife Lydia (appellants) on a 

theory of strict liability failure to warn. The trial court, however, granted Taylor-Dunn’s 

motion for judgment notwithstanding the verdict on the ground that there was insufficient 

evidence to support the jury’s finding that failure to warn was a substantial factor in 

causing appellants’ harm.

Appellants contend the judgment must be reversed because substantial evidence 

and reasonable inferences from that evidence support the jury’s finding that the absence 

of a warning caused Corbo’s injuries. We reject this contention and affirm the judgment.
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II. STATEMENT OF FACTS

A. The Accident

1. Background

On October 3, 2007, Corbo’s foot was seriously injured during an accident that 

occurred at the New United Motor Manufacturing Plant (the NUMMI plant) in Fremont, 

Alameda County. At the time, Corbo was employed by CTS Advantage Logistics (CTS), 

which provided shipping, moving and management services at the NUMMI plant. 

Corbo’s direct supervisor was Sergio Fernandez who was employed by Vascor, Ltd., the 

contractor responsible for coordinating all logistical services at the NUMMI plant. 

Corbo’s foot was crushed when it was pinned between a metal stairwell outside a

truck dock and the front end of an electric vehicle manufactured by Taylor-Dunn. The 

vehicle, described by trial witnesses as both a truck and a cart, was an open top vehicle 

with a 76-inch long flatbed separated from the passenger area by a 24-inch high metal 

partition. The front passenger area contained two seat cushions separated by a parking 

brake. The truck was operated by a toggle switch with three positions (Forward, Neutral, 

Reverse) and a floor brake pedal and accelerator pedal. 

The front passenger area of the truck contained two posted warnings: (1) a 

“Safety Warning” consisting of a list of admonitions about what to do “Before Operating 

The Vehicle,” “While Operating The Vehicle,” and “Before Leaving or Servicing The 

Vehicle”; and (2) a decal warning showing the driver and passenger to keep extremities 

inside the vehicle. The list of admonitions on the Safety Warning label included 

instructions that “All occupants must be seated in manufacturer’s approved seats”; not to 

engage in “horseplay”; and to “Apply Parking Brake.”1 

When the accident occurred, three men who worked at the NUMMI plant were in 

the front passenger area of the Taylor-Dunn truck. Tai Lam was in the driver’s seat, 

 

1

 The factual summary in the appellants’ opening brief does not include any 

discussion of the safety warnings that were affixed to the truck. Because this is not the 

only relevant evidence appellants fail to mention, we encourage them to review the 

pertinent rules of court governing appellate briefs that are filed in this court.
3

Davin Castro was in the passenger seat, and Sergio Fernandez was sitting or standing in 

between them. At trial, the jury heard different versions of the accident from the four 

individuals who were involved.

2. Christopher Corbo

Corbo testified that, near the end of his work day, he and Fernandez drove to the 

truck dock to generate some paperwork for a truck that was going to be driven off the 

plant that day. Fernandez was already inside the building and Corbo was about to go 

inside when he heard someone yell his name. Corbo turned and saw the Taylor-Dunn

truck approaching the dock. Corbo knew Lam, the driver, and his passenger, Castro, both 

of whom worked for a different company that provided services at the NUMMI plant. 

Lam pulled up and stopped the truck about three or four feet back from the stairwell 

leading up to the office. 

Corbo assumed the men had a work-related question and went down the stairs to 

see what they needed, stopping directly in front of the Taylor-Dunn truck. Corbo could 

not hear the motor running, and did not see any lights on or any other indication that the 

truck was still in operation or “potentially capable of movement.” Corbo stood 

approximately six inches from the front of the truck with his hands resting on the top rail

and talked with Lam about a part that Lam needed and possibly some other work-related 

matters. A few minutes later, Corbo heard Fernandez come out of the office and down 

the stairs. 

Corbo saw Fernandez walk over to the pickup truck they had been using and then 

to the back of the flatbed truck that Lam was driving. Fernandez climbed onto the back 

of the Taylor-Dunn flatbed and then over the partition and sat down in between Lam and 

Castro. At that point, Corbo had already taken his hands off the truck bar but he was still 

standing only six inches from the front of the truck and he continued to converse with the 

others for at least a few minutes. Then, the truck “lunged” forward, and Corbo took a 

few steps back before realizing he could not go any farther because the stairwell was 

behind him. Corbo felt the stairwell hit the middle of his back and the bottom of the 
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truck hit and “cut through” his left foot, and then come to a stop when it hit the stair 

behind his leg.

3. Sergio Fernandez

Fernandez testified that the accident occurred after he and Corbo had finished their 

work in the office at the truck dock. According to Fernandez, when he and Corbo came 

out of the office together, the Taylor-Dunn truck was already there, stopped several feet 

in front of the stairwell, and Lam and Castro were sitting in the truck, each with one leg 

over the side resting on the ground, taking a cigarette break. 

Fernandez testified that Corbo stopped to talk while he went over to the pickup 

they had been driving and put his clipboard inside. Fernandez could not recall anything 

about the conversation other than that the three men laughed and it appeared they would 

talk for a while. So Fernandez went around to the back of the flatbed and climbed in. 

When he reached the front of the truck, he placed one hand on Lam’s shoulder and the 

other on Castro’s shoulder, climbed over the partition, and then sat down. There was 

plenty of room for him and he sat comfortably, partially on the driver’s cushion and 

partially on the passenger’s cushion, with his hands in his lap. Approximately 45 seconds 

later, the flatbed began to move. Then, Fernandez felt a “jerk” motion, the truck seemed 

to pick up speed, and it did not come to a stop until it made contact with the metal 

stairwell behind Corbo. 

4. Tai Lam

Lam testified that he and Castro were using the Taylor-Dunn truck to locate a 

pallet of parts at one of the docks when they saw Corbo standing on the exterior stairwell 

at the truck dock. Lam called out to Corbo and then stopped the truck about four feet 

from the staircase, moved the “toggle switch” on the truck from Forward to Neutral, and 

placed his right foot on the floor of the truck under the brake pedal. He did not turn off 

the ignition or engage the parking brake. 

Corbo came down the stairs and stood in front of the truck. Less than a minute 

later, Fernandez came out of the office and Corbo called him over, suggesting that they

“do a threesome in the cart.” Fernandez, who was holding a clipboard, walked past the
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side of the truck while Corbo put his hands on the top bar and began pushing down on it. 

Then Fernandez climbed onto the back of the flatbed and proceeded to climb over the 

barrier into the passenger area of the truck. He put his left hand on Lam’s shoulder while 

he held the clipboard in his right. As Fernandez brought his left leg over the barrier, he 

kicked Lam in the thigh, and the clipboard hit the toggle switch, pushing it into Forward. 

Then Fernandez dropped his left foot directly onto the accelerator pedal. Almost 

immediately, the truck began to move forward. Lam acknowledged that he did not take 

any action to stop the truck until after it made contact with the stairwell, at which point he

moved the toggle switch from Forward to Reverse and backed it away from Corbo. 

5. Davin Castro2

Castro testified that Lam was giving him a ride in the Taylor-Dunn truck when 

Corbo, who was sitting on the stairwell in front of the truck dock, called out to them. As 

Lam headed toward him, Corbo stood, walked forward a few feet and stopped. Lam 

stopped the flatbed a few feet in front of him. Castro was not paying attention to how 

Lam was driving, but he did recall that Lam moved the toggle switch to Neutral 

immediately after he stopped the truck. The three men exchanged greetings and then 

Corbo and Lam began to discuss a shipment of parts that was being delivered. 

Very quickly thereafter, Fernandez came out of the office carrying a clipboard, 

said hello and then walked toward the pickup saying he would be right back. While 

Corbo and Lam continued their conversation, Corbo had his hands on a bar running 

across the front of the flatbed and was shaking the truck by pushing his weight down and 

up. The next thing Castro knew, Fernandez jumped into the cart, came up behind them 

and hopped in between Castro and Lam. Fernandez had not said anything before he did 

this and Castro was very surprised by the sudden movement. 

Castro testified that when Fernandez jumped into the passenger area of the cart, 

both Castro and Lam had their legs inside the truck. There was no room between them 

 

2

 Pursuant to a stipulation between the parties, excerpts from Castro’s deposition 

were read to the jury at trial. 
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for Fernandez, who still had his clipboard in his hand, and that is when the accident 

occurred. Castro could not recall if Fernandez landed squarely on the floor with both feet 

but testified that he landed on some area near the floor and that “the forward momentum 

of him jumping forward pushed him into the dashboard of the cart,” and the truck began 

to move forward “[a]lmost immediately.” Castro admitted that he did not see any part of 

Fernandez’s body hit the toggle switch, but testified that the clipboard that Fernandez was 

holding was directly over that switch just before the truck started to move. 

B. The Accident Investigation

An investigation of Corbo’s accident was conducted by Azadeh Morrison, 

NUMMI’s Health and Safety Specialist. Morrison arrived at the truck dock while Corbo 

was receiving medical treatment, but waited until he was taken to the hospital to 

interview Lam, Castro and Fernandez. The group gave a very general account of the 

accident: Lam and Castro were in the stopped truck talking with Corbo; Fernandez 

climbed into the truck from the back; the truck moved forward; and Corbo was pinned 

between the truck and the stairwell. Although the report was short on details, Fernandez 

did deny that his foot hit the accelerator. 

After Morrison returned to her office at the plant, she received a message that Lam 

and Castro wanted to talk with her. During the meeting that followed, the two men 

reported they had not been comfortable talking about the accident in front of Fernandez

and that they wanted to clarify what happened. They told Morrison that they had been 

talking to Corbo when Fernandez arrived, that Corbo suggested that Fernandez climb in 

the flatbed so they could have a “threesome,” that Lam had put the truck in the Neutral 

position but a clipboard Fernandez was holding hit the switch and flipped it to the 

Forward position; and that when Fernandez climbed in between them, his foot hit the 

accelerator pedal. 

During her investigation, Morrison determined that the individuals involved in the 

Corbo accident had not received special training regarding the use of flatbed trucks but 

that Lam, Fernandez and Corbo had all received training to operate a forklift. As part of 

that training, they were advised regarding NUMMI’s “[g]eneral driving rules” for
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operating mobile equipment at the plant. Those rules prohibited, among other things,

smoking in vehicles, horseplay and stunt driving. In addition, only one person was to 

occupy a seat in a vehicle at any time, and drivers were instructed not to stop the vehicle 

in front of a person standing in front of a fixed object.

Morrison arranged for an inspection of the Taylor-Dunn truck by the NUMMI 

maintenance department. She had conducted a preliminary test at the accident scene, 

driving it backward, forward and engaging the brake, and found no indication that the 

vehicle could have moved from a stopped position without somebody depressing the 

accelerator. The inspection performed at the plant’s maintenance department confirmed 

that all of the systems on the flatbed truck were in proper working order. 

At the instruction of NUMMI attorneys, Morrison did not complete her 

investigation of the accident. However, based on the information she gathered and her 

own experience driving flatbed trucks, Morrison concluded that the Taylor-Dunn truck 

involved in this accident could not have moved forward unless someone stepped on the 

accelerator pedal. At trial, appellants’ expert engineer, John Manning, acknowledged 

finding no indication that the flatbed was capable of “spontaneous movement.” 

C. The Present Action

Appellants’ October 2009 complaint alleged causes of action against Lam, 

Fernandez, Taylor-Dunn and several other defendants. However, Taylor-Dunn was the 

only remaining defendant in the case when a jury trial commenced in August 2011, 

before the Honorable Ronni B. MacLaren. 

Appellants’ claim at trial was that Taylor-Dunn was strictly liable for their 

damages because the design of the flatbed truck caused Corbo’s injuries. They attempted 

to show that the truck design was defective under three distinct theories: (1) a consumer 

expectation theory, that the truck did not perform as safely as an ordinary consumer 

would have expected it to perform; (2) a risk/benefit theory, that the truck design was a 

cause of Corbo’s injuries and that the risks of the design were not outweighed by its 

benefits; and (3) a failure to warn theory, that the truck lacked sufficient instructions or 

warnings about the risks of harm.
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Appellants’ primary factual theory at trial was that the collision happened 

“because of the accidental movement of the toggle into drive, coupled with acceleration.” 

Under this theory, the alleged defect in the Taylor-Dunn truck was that it “had a defective 

drive toggle, switch mechanism, that could accidentally be engaged.” And the risk of 

harm which allegedly gave rise to a duty warn was the risk that human operators make 

mistakes and people accidentally bump into things. Taylor-Dunn’s trial theory was that 

Lam never actually put the toggle switch in the Neutral position but simply left it in the 

Forward position when he stopped to talk to Corbo, and then, when Fernandez jumped in, 

somebody’s foot hit the accelerator. Under this theory, Taylor-Dunn was not strictly 

liable for Corbo’s injuries because the cause of the accident was horseplay, a misuse of 

the vehicle, and not the design of the flatbed truck.

At the conclusion of the trial, the jury rejected appellants’ consumer expectation 

theory and risk/benefit theory, but found that Taylor-Dunn was strictly liable for

appellants’ damages because it failed to warn about the risk associated with the flatbed 

truck. Pursuant to a special verdict form, the jury found that (1) the truck had a potential 

risk that was known or scientifically knowable at the time it was manufactured; (2) the 

potential risk presented a substantial danger to users of the truck; (3) an ordinary 

consumer would not have recognized the potential risk; (4) Taylor-Dunn failed to 

adequately warn or instruct about the risk; and (5) the lack of sufficient instructions or 

warnings was a substantial factor in causing the plaintiffs’ harm.

The jury also found that the negligence of several other actors were substantial 

factors causing Corbo’s harm, and it apportioned fault as follows: Lam – 35 percent; 

Fernandez – 30 percent; NUMMI – 20 percent; Taylor-Dunn – 9 percent; Vascor – 4

percent; Corbo – 2 percent. 

On December 28, 2011, Taylor-Dunn filed a motion for partial judgment 

notwithstanding the verdict (JNOV) on the ground that there was insufficient evidence to 

support the jury’s finding that failure to warn was a substantial factor causing Corbo’s 

injuries.
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On January 6, 2012, the court entered judgment holding that Taylor-Dunn was 

liable to appellants for damages in the total amount of $1,383,417.86, plus costs and 

interest.

On January 27, 2012, the trial court conducted a hearing on the motion for JNOV, 

at the conclusion of which it requested supplemental briefing. After a second hearing on 

March 9, the court took the matter under submission. On April 2, 2012, the court granted 

the motion for JNOV in a detailed order the conclusion of which was that “there was no 

evidence from which the jury could have reasonably concluded that it was more likely 

than not that the accident would not have occurred if one of the warnings proposed by 

Plaintiffs had been provided.” Thus, the trial court vacated the judgment and entered a

new judgment in favor of Taylor-Dunn.

III. DISCUSSION

Appellants contend that the trial court erred by granting the JNOV because the

evidence supports the jury’s finding that the absence of a warning caused Corbo’s 

injuries. “ ‘ “ ‘ “A motion for [JNOV] may properly be granted only if it appears from 

the evidence, viewed in the light most favorable to the party securing the verdict, that 

there is no substantial evidence to support the verdict. If there is any substantial 

evidence, or reasonable inferences to be drawn therefrom, in support of the verdict, the 

motion should be denied.” [Citation.]’ ” [Citation.]’ [Citation.] In reviewing an order 

denying a JNOV, we draw all reasonable inferences in favor of the jury’s verdict. 

[Citation.]” (Cash v. Winn (2012) 205 Cal.App.4th 1285, 1304.)

A. Legal Principles

In California, strict products liability law recognizes three types of product 

defects: (1) manufacturing defects, (2) design defects, and (3) warning defects. 

(Anderson v. Owens-Corning Fiberglas Corp. (1991) 53 Cal.3d 987, 995.) This appeal 

pertains to the third category, “which applies to ‘products that are dangerous because they 

lack adequate warnings or instructions.’ [Citation.]” (Taylor v. Elliott Turbomachinery 

Co., Inc. (2009) 171 Cal.App.4th 564, 577 (Taylor).)
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“Our law recognizes that even ‘ “a product flawlessly designed and produced may 

nevertheless possess such risks to the user without a suitable warning that it becomes 

‘defective’ simply by the absence of a warning.” [Citation.]’ [Citation.] Thus, 

manufacturers have a duty to warn consumers about the hazards inherent in their 

products. [Citation.] The purpose of requiring adequate warnings is to inform consumers 

about a product’s hazards and faults of which they are unaware, so that the consumer may 

then either refrain from using the product altogether or avoid the danger by careful use. 

[Citations.] (Taylor, supra, 171 Cal.App.4th at p. 577.) Accordingly, California holds 

“manufacturers strictly liable for injuries caused by their failure to warn of dangers that 

were known to the scientific community at the time they manufactured and distributed 

their product. [Citations.]” (Johnson v. American Standard, Inc. (2008) 43 Cal.4th 56, 

64-65.) 

However, “[t]o be liable in California, even under a strict liability theory, the 

plaintiff must prove that the defendant’s failure to warn was a substantial factor in 

causing his or her injury. [Citation.]” (Huitt v. Southern California Gas Co. (2010) 188 

Cal.App.4th 1586, 1604 (Huitt); see also Rutherford v. Owens-Illinois, Inc. (1997) 16 

Cal.4th 953, 968 (Rutherford); Conte v. Wyeth, Inc. (2008) 168 Cal.App.4th 89, 112

(Conte); CACI No. 1205 [plaintiff has burden of proving that lack of sufficient warnings 

or instructions was a substantial factor in causing plaintiff’s harm].) “The natural 

corollary to this requirement is that a defendant is not liable to a plaintiff if the injury 

would have occurred even if the defendant had issued adequate warnings. [Citation.]” 

(Huitt, supra, 188 Cal.App.4th at p. 1604.)

B. Analysis

As reflected in our factual summary, the jury found that Taylor-Dunn’s failure to 

warn about a risk associated with the electric truck caused Corbo’s injury. However, the 

jury did not identify what risk the truck presented or what warning would have made a 

difference.

Appellants maintain that the risk of harm that gave rise to a duty to warn was that 

the flatbed would “suddenly and silently lurch forward and pin [Corbo] against a 
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stairway, causing serious and permanent injuries.” With a variety of embellishments, this 

notion runs throughout their arguments on appeal. However, the record does not support 

this characterization of the risk associated with the flatbed because the jury rejected 

appellants’ two theories of strict liability for defects in a product design. Indeed, the 

special verdict form contains an express finding that the design of the Taylor-Dunn truck 

was not a substantial factor causing Corbo’s injury. Thus, the jury necessarily rejected 

testimony by Fernandez and Corbo that the flatbed suddenly lurched forward for no 

reason even though nobody stepped on the accelerator. 

As noted in our factual summary, during closing argument, appellants’ trial 

counsel argued that the risk of harm was that human operators make mistakes and that 

people accidentally bump into things. In other words, the risk was that the shift 

mechanism and accelerator on the flatbed could be unintentionally engaged. For 

purposes of this appeal, we will assume that the jury accepted this characterization of the 

risk of harm, which is supported by the evidence. 

As best we can determine, appellants never clearly articulated for the jury how a 

warning about this risk should have been communicated by Taylor-Dunn. In this court,

appellants contend that the jury could have based its liability finding on the absence of 

any one of three warnings: (1) a sign, light or signal on the front exterior of the truck 

warning pedestrians not to stand in front of the truck; (2) a warning label affixed to the 

interior of the truck cautioning the driver not to park the truck and remain in the driver’s 

seat without turning off the ignition and engaging the parking brake; and (3) an interior 

sticker warning passengers not to have three people in the front seat.

Preliminarily, we reject appellants’ contention that the absence of an exterior 

warning light or audible signal caused Corbo’s injury. As the trial court explained in its 

order granting the JNOV, the absence of some form of sound or light signal that the 

motor was running is an alleged design defect which cannot support a liability finding 

based on failure to warn under the circumstances of this case because the jury rejected 

appellants’ design defect theories. Thus, in addressing appellants’ arguments on appeal, 

we limit our analysis to hypothetical warning labels or stickers that could have been
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affixed to the Taylor-Dunn electric vehicle on locations that would have been in the line 

of view of the individuals involved in Corbo’s accident.

During the JNOV proceedings, appellants did not dispute that “there was no 

testimony at trial that any of the individuals involved in the injury-causing incident 

testified that he would have heeded a warning, if one had been provided.” Indeed, Corbo 

did not testify that, if he had seen a warning label on the exterior of the Taylor-Dunn 

truck, he would have stopped to read it and then acted differently than he did when the 

accident occurred. Lam did not testify that he would have taken notice of or complied 

with any warning label about sitting in the driver’s seat without turning off the ignition or 

engaging the parking brake. Nor did Fernandez or any other witness testify that he would 

have acted differently had he seen a warning label to not have three people in the front 

seat. 

On appeal, appellants spend significant time arguing that direct evidence of 

causation is not required in a strict liability failure to warn case. They contend, among 

other things, that such self-serving testimony regarding a “[h]indsight [t]ruism” wastes 

times, lacks substantive weight, and will almost always elicit an objection from the 

defense. We are perplexed by these arguments. 

Courts in this state have long recognized that proving causation in a defective 

products case can be difficult and, indeed, that direct evidence of causation may not exist. 

(Dimond v. Caterpillar Tractor Co. (1976) 65 Cal.App.3d 173, 183 (Dimond).) Thus, a 

plaintiff may carry his burden of proving causation by circumstantial evidence. (Ibid.) 

Furthermore, as best we can tell, there has never been any dispute in this case that the 

causation element of a failure to warn claim can be proven with circumstantial evidence. 

In fact, the jury was instructed pursuant to CACI No. 202, that “[s]ome evidence proves a 

fact directly,” that “[s]ome evidence proves a fact indirectly,” that indirect evidence is 

sometimes referred to as “ ‘circumstantial evidence,’ ” and that “As far as the law is 

concerned, it makes no difference whether evidence is direct or indirect.” 

Appellants strongly intimate that the trial court erroneously demanded direct 

evidence of causation. However, the order granting the JNOV contains an express 
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finding that “None of the testimony cited by Plaintiffs provides a basis from which it can 

be logically and reasonably inferred that any of the participants would have altered his 

conduct, in a way that would have prevented Plaintiff Corbo’s injuries, if he had seen a 

warning.” Thus, the court granted the JNOV because if did not find sufficient direct or 

circumstantial evidence to support the jury’s causation finding.

Our review of the evidence leads us to the same conclusion the trial court reached. 

It remains undisputed that there is no direct evidence that the absence of these warnings 

caused this accident to happen. Nor do we find substantial circumstantial evidence of 

causation in the trial record. For example, there is no evidence suggesting any of the 

individuals involved in this accident are careful people, or that they looked for, were 

concerned by, or followed warnings regarding the performance of their job duties at the 

NUMMI plant. Nor were there any circumstances about this particular incident which 

suggest in any way that the people involved would have acted differently if one of 

appellants’ hypothetical warnings had been affixed to the electric truck. 

Appellants insist that this record supports an inference that the absence of an 

adequate warning caused this accident. They maintain that “the only reasonable—

indeed, virtually inescapable—inference, which the jury was allowed to make and did in 

fact make, is that Corbo would have heeded a warning not to stand in front of TaylorDunn’s truck if he had known that it would suddenly and silently lurch forward and pin 

him against a stairway, causing serious and permanent injuries.” But the issue is not 

whether Corbo would have heeded a warning had he known that failure to do so would 

cause him injury. The pertinent question is whether, without the benefit of that hindsight 

knowledge, Corbo or one of the other three men would have altered their conduct in a 

way which would have avoided the accident if the truck had contained a specific warning 

about the danger of a negligent or accidental acceleration. 

“An inference is a deduction of fact that may logically and reasonably be drawn 

from another fact or group of facts found or otherwise established in the action.” (Evid. 

Code, § 600, subd. (b)) In other words, an inference must be drawn from the evidence. 

(Collin v. American Empire Ins. Co. (1994) 21 Cal.App.4th 787, 808 (Collin).) 
14

Appellants do not identify any evidence to support an inference that the absence of a 

warning was a substantial factor causing this accident. Dimond, supra, 65 Cal.App.3d 

173, a case upon which appellants’ mistakenly rely, illustrates our point. 

Dimond was a strict liability product defect case against the manufacturer of a 

forklift that plaintiff was using when he suffered serious personal injuries during a 

warehouse accident. The plaintiff alleged that the forklift was defective both in its design 

and because it was accompanied by a defective warning. (Dimond, supra, 65 Cal.App.3d 

at p. 176.) To prove these claims, the plaintiff produced evidence that he sustained his 

injuries while working alone in a warehouse, using the forklift to move and store

packaged rolls of printing paper weighing approximately 550 pounds each. (Id. at p. 

177.) Co-workers found the plaintiff after they heard a “loud boom” in the warehouse. 

He was face-down on the ground behind the forklift, with his feet closest to it. Two of 

the 550 pound rolls were on top of the plaintiff and a third roll was on the other side of 

the forklift. There was a dent in the overhead protective cage of the forklift which had 

not been there when the plaintiff started his shift; the “clamp” component of the forklift 

was secured around a stack of papers; and the gear shift was in the neutral position,

although the motor was still running. (Id. at p. 178.) 

At trial, the Dimond plaintiff was unable to recount the circumstances of the 

accident itself because his injuries caused retrograde amnesia. (Dimond, supra, 65 

Cal.App.3d at p. 178.) Nevertheless, he testified that he had seen warnings in the 

operator’s manual and on the forklift itself which advised that the overhead cage would 

not afford protection against “ ‘heavy or capacity loads.’ ” (Ibid.) Plaintiff also testified 

that he had feared that something might hit the exposed propane tank on the forklift and 

cause an explosion to occur. Finally, plaintiff testified that he always placed the forklift 

gear in neutral and turned off the motor before he dismounted the vehicle. (Ibid.) At 

trial, the plaintiff also presented expert testimony that the position of the propane tank 

rendered the forklift defective and that the posted warning regarding the strength of the 

overhead cage was inadequate and defective because it was ambiguous and dangerously 

misleading. (Id. at p. 179.) 
15

After the Dimond plaintiff presented his case at trial, the court granted a nonsuit to 

the defendant on the ground there was insufficient evidence to establish causation. 

(Dimond, supra, 65 Cal.App.3d at p. 180.) The Dimond court reversed. The court 

reasoned that, in order to accept the plaintiff’s theory of liability, the factfinder would 

have to draw two inferences: (1) that the plaintiff was on the forklift when the paper rolls 

began to fall; and (2) that the plaintiff left the “safe enclosure of the overhead guard” 

either because of the misleading warning or because of the positioning of the exposed 

propane tank. Finding that substantial circumstantial evidence supported these

inferences, the court concluded that the nonsuit should not have been granted. (Id. at pp. 

180-183.) 

Regarding the element of causation, the Dimond court acknowledged plaintiff’s 

amnesia precluded his direct testimony on this issue. (Dimond, supra, 65 Cal.App.3d at 

p. 182.) Nevertheless, causation was established by evidence that the plaintiff had read 

the misleading warnings that the overhead cage would not protect him from a heavy or 

capacity load and that plaintiff feared a possible explosion from a falling object striking 

the propane tank. In light of this evidence, the court found, “[i]t is a perfectly logical and 

reasonable deduction that when confronted with a falling object of substantial weight, 

plaintiff acted in conformity with his expressed concerns.” (Id. at p. 185.) 

Dimond illustrates that direct evidence of causation is neither required nor 

necessary to establish the causation element of a strict product liability failure to warn 

claim. But, as the Dimond court underscored, that does not mean that the burden of proof 

shifts to the defendant; causation can be inferred, but only when there is sufficient 

circumstantial evidence to support that inference. (Dimond, supra, 65 Cal.App.3d at p. 

184.) In the present case, appellants have not identified any direct or circumstantial 

evidence in this record which substantially supports the jury’s finding that the absence of 

a warning about the risk of using the Taylor-Dunn flatbed truck was a substantial factor 

causing this accident. 

In fact, many circumstances established or supported by the trial evidence are 

inconsistent with the inference that the warning labels appellants propose would not have 
16

prevented this accident. First, as reflected in our factual summary, the Taylor-Dunn truck 

did have a Safety Warning label. Yet the circumstances show that Lam, Castro and 

Fernandez ignored several of the admonitions listed on that warning. Furthermore, to the 

extent the jury credited Fernandez’s version of the accident, Lam and Castro also ignored 

the decal advisement to keep their legs inside the vehicle. 

Second, as we also note above, Corbo, Fernandez and Lam received training 

regarding operating a forklift, which included advisement regarding the “[g]eneral 

driving rules” at the NUMMI plant. In addition, Gary Durham, who was Fernandez’s 

direct supervisor at the time of the accident, testified that he discussed several of these 

rules with Fernandez and Corbo.3 Although there was conflicting evidence regarding 

compliance with some of these safety rules (e.g., smoking in the vehicle, horseplay), 

undisputed evidence shows that these men did not follow the general rules that only one 

person was to occupy a seat in a vehicle at any time and that a driver was not to stop a 

vehicle in front of a person standing in front of a fixed object. 

Third, evidence presented at trial showed that Lam and Castro were not only 

aware of the rule against having three people in a vehicle seat that was designed for two 

people, they had been disciplined for violating that rule in the past. At trial, Lam 

admitted that, on an occasion before Corbo’s accident, he and Castro were “busted” by a 

supervisor for having three people in the front seat of a golf cart. 

In their reply brief, appellants contend these circumstances are not dispositive 

because the jury was not required to draw the inference Taylor-Dunn wanted, i.e., that the 

individuals involved in this accident would not have heeded a warning. This argument 

misperceives the burden of proving causation. Appellants had that burden and they did 

not produce sufficient circumstantial evidence to support an inference of causation. 

Taylor-Dunn did not have the burden of rebutting an inference that was never established. 

 

3

 Durham also testified that Fernandez had a reputation among his co-workers as 

someone who goofed around.
17

Finally, appellants argue that, to the extent the resolution of this issue depends on 

an inference, the “telling fact is that Corbo was crushed because he was standing in front 

of the truck when it lurched forward. That fact supports an inference he would not have 

stood in front of the truck had he been warned of the danger. There was no evidence, for 

example, that Corbo did not care whether he was crushed against a stairwell.”

This final argument highlights a flaw that runs throughout appellants’ arguments 

on appeal. If the fact of injury itself was sufficient to support an inference of causation, 

then causation would never be an issue in a failure to warn strict products liability case. 

That simply is not the law; the plaintiff has the burden of proving causation and he cannot 

sustain that burden if there is no evidence that a warning would have made any 

difference. In other words, the question is not what Corbo would have done had he 

known his foot would be pinned between the truck and metal stairs but, rather, whether 

he would have heeded a warning not to stand in front of the truck even though he did not 

know that the accident was about to happen.

C. Appellants’ Alternative Theories for Proving Causation

Although appellants fail to squarely acknowledge the evidentiary void in this case, 

they propose two alternative grounds upon which to affirm the jury’s causation finding: 

(1) that causation in this context is a question of common sense which can be established 

by asking what a reasonable person in Corbo’s position would have done had a warning 

been provided; and (2) that this court should recognize a “presumption” that Corbo would 

have heeded a warning if one had been provided. 

1. The Reasonable Person Test

Claiming to raise a question of first impression under California products-liability 

law, appellants ask this court to find that an “objective reasonable-person test” 

substantially supports the jury’s causation finding in this case. Appellants contend that 

the causation element of a failure to warn claim is different than causation in other types 

of product liability cases because an inquiry about what an actor would have done if a 

warning had been given is inherently speculative. Therefore, appellants posit that 
18

employing an objective reasonable person analysis to determine whether the absence of a 

warning caused a plaintiff’s harm would be the most equitable way to resolve this issue.

The first problem with this theory is that it is not the theory upon which this case 

was tried and this jury was instructed. The trial court used a version of CACI No. 1205 

to instruct the jury regarding the essential factual elements of appellants’ strict liability 

failure to warn claim. That instruction stated that plaintiffs were required to prove seven 

elements, the last of which was “That the lack of sufficient instructions or warnings was a 

substantial factor in causing Christopher Corbo’s harm.” We find no indication in the 

record that appellants objected to this instruction or requested any special instruction 

regarding the causation element of its failure to warn claim. 

Another problem with appellants’ reasonable person test for proving causation is 

that it does not raise a “question of first impression” as appellants contend. (See Saelzler

v. Advanced Group 400 (2001) 25 Cal.4th 763 (Saelzler); Huitt, supra, 188 Cal.App.4th 

1586.) 

In Saelzler,supra, 25 Cal.4th 763, plaintiff sued a business owner for injuries she 

sustained during a criminal assault that occurred on the defendant’s premises. In 

affirming a plaintiff’s verdict, the Court of Appeal adopted a “practical approach to the 

causation issue” by relying on “common sense and common experience” to conclude that 

the absence of required security measures at the defendant’s premises was a contributing 

cause of the crime. (Id. at p. 778.) However, the Supreme Court reversed the judgment

on the ground there was insufficient evidence of causation. The court reasoned that the 

Court of Appeal’s common sense approach was not based in the evidence, and was 

fundamentally unfair to the defendant because it permitted a lay jury to make an after the 

fact determination of causation. As the court explained, “if we simply relied on 

hindsight, the mere fact that a crime has occurred could always support the conclusion 

that the premises were inherently dangerous.” (Ibid.) 

Thus, the Saelzler court held that “to demonstrate actual or legal causation, the 

plaintiff must show that the defendant’s act or omission was a ‘substantial factor’ in 

bringing about the injury. [Citations.] In other words, plaintiff must show some 
19

substantial link or nexus between omission and injury.” (Saelzler, supra, 25 Cal.4th at p. 

778.) The Court of Appeal’s “ ‘common sense’ ” rule, was inconsistent with this test 

because under that faulty approach “the defendants’ omission itself would constitute the 

missing link.” (Ibid.) The Saelzler court also rejected the appellant’s contention that the 

substantial factor test for proving causation would make it “virtually impossible” to prove 

a negligence claim against a landlord or property owner for failure to take reasonable 

protective measures to safeguard others from a third party criminal assault. (Id. at p. 

779.) The court reasoned that it could readily imagine a case in which “direct or 

circumstantial evidence” would establish the requisite substantial causal link between the 

third party assault and the defendant’s negligence, although no such evidence was 

produced by the appellant. (Ibid.)

Finally, the Saelzler court rejected appellant’s contention that the circumstances 

justified shifting the burden of proving causation to the defendant. (Saelzler, supra, 25 

Cal.4th at p. 779.) The Court of Appeal had accepted that notion, finding that the 

defendant’s “flagrant failure to provide daytime security justified shifting the burden of 

proof to defendants to conclusively establish the absence of a causal relation between its 

breach of duty and the assault on plaintiff . . . .” (Id. at pp. 779-780.) However, the 

Saelzler court strongly disagreed, holding that “[n]o matter how inexcusable a 

defendant’s act or omission might appear, the plaintiff must nonetheless show the act or 

omission caused, or substantially contributed to, her injury. Otherwise, defendants might 

be held liable for conduct which actually caused no harm, contrary to the recognized 

policy against making landowners the insurer of the absolute safety of anyone entering 

their premises. [Citations.]” (Id. at p. 780.)

The Saelzler holdings were applied in a strict liability failure to warn case in Huitt, 

supra, 188 Cal.App.4th 1586. The Huitt plaintiffs were injured while attempting to light 

a water heater at a construction site. When the heater would not light, they decided to 

bleed any accumulated air in the natural gas pipe. However, when they made another 

attempt to light the pilot light, the gas that had been released into the water heater closet 

exploded and plaintiffs were seriously injured. (Id. at p. 1588.) In the strict liability 
20

action that followed, plaintiffs alleged the defendant gas company had a duty to warn 

them that new steel gas pipes absorb an odorant which is added to natural gas so that its 

presence is detectable. Plaintiffs also alleged that the breach of that duty to warn caused 

their injuries because if plaintiffs had known about the odor fade they would not have 

bled the gas pipe into the water heater closet. The jury accepted this theory and awarded 

plaintiffs compensatory and punitive damages. (Ibid.)

The Huitt court reversed the judgment, finding insufficient evidence that the 

defendant’s failure to issue a warning was a substantial factor causing the plaintiffs’ 

harm. (Huitt, supra, 188 Cal.App.4th at pp. 1589, 1596-1600.) The court reasoned that 

the primary causation issue presented by the facts was whether there was any effective 

way that a warning issued by the gas company would have reached the plaintiffs. No 

evidence was produced to support an affirmative response to that question. Instead, the 

plaintiffs relied solely on “common sense and common experience to convince the jury 

that if a warning had been issued, the accident would have been avoided.” (Id. at p. 

1602.) Then the trial court permitted the jury to use “hindsight to conclude that plaintiffs 

would have acted differently if they had known of the odor fade.” (Ibid.) The Huitt court 

found that this “approach” was error because it permitted the jury to ignore the causation 

element of the failure to warn claim. (Ibid.) 

Appellants’ reasonable person test for proving causation is just another label for 

the common sense approach disapproved in Saelzler and Huitt. Adopting such a test 

would relieve the plaintiff of his burden of proving the causation element of a failure to 

warn claim by authorizing the jury to speculate about what a hypothetical reasonable 

person would do rather than basing its causation determination on the evidence in the 

case. In their opening brief to this court, appellants ignore Saelzler and, in their reply 

brief, they take the position that Saelzler is inapposite because it was not a strict liability 

failure to warn case. However, the Saelzler court addressed the same substantial factor 

test that California uses to determine causation in a failure to warn case. Furthermore, 

Huitt applied the Saelzler holding to resolve the same issue raised by this appeal. 
21

Contending that our Supreme Court has already tacitly approved a reasonable 

person test for proving causation, appellants direct our attention to Cobbs v. Grant (1972) 

8 Cal.3d 229, 245 (Cobbs).) The Cobbs court addressed the elements of a medical 

malpractice case based on a theory that a doctor’s failure to disclose the risks of surgery 

vitiated the plaintiff’s consent to an operation. The court confirmed that informed 

consent cases require a causal relationship between the physician’s failure to inform and 

the plaintiff’s injury. (Ibid.) But the court also acknowledged problems inherent in a 

plaintiff’s testimony on this subject since, at the time of trial, the uncommunicated hazard 

has already materialized. Thus, the court found that “an objective test is preferable: i.e., 

what would a prudent person in the patient’s position have decided if adequately 

informed of all significant perils.” (Ibid.) As appellants contend, this objective standard

for proving causation is also embodied in standard jury instructions regarding informedconsent medical malpractices cases. CACI No. 533 states that, in order to establish 

causation, the plaintiff must show “[t]hat a reasonable person” in the plaintiff’s position 

would not have agreed to the procedure if he had been fully warned of its risks.

However, appellants overlook the fact that this is not a medical malpractice case. 

They provide no reason or authority for their assumption that the policies underlying 

medical malpractice law should apply in this very different context. More to the point,

because this is not a medical malpractice case, CACI No. 533 was not the causation 

instruction that was given to the jury in this case. Here, the jury was instructed—without 

objection—that the plaintiffs had the burden of proving that the alleged failure to warn 

about a risk of the flatbed truck was a substantial factor causing harm. That substantial 

factor test cannot be satisfied by resort to common sense or an objective reasonable 

person test. (Saelzler, supra, 25 Cal.4th 763; Huitt, supra, 188 Cal.App.4th 1586.) 

2. The Heeding Presumption

Appellants’ second argument is that the jury’s verdict can be sustained by giving 

Corbo the benefit of a “heeding presumption” that he would have heeded a warning not 

to stand in front of the Taylor-Dunn flatbed if such a warning had been given. 
22

Courts in some jurisdictions have applied a heeding presumption to the causation 

element of product-liability cases based on a failure to warn theory. (See Coffman v. 

Keene Corp. (1993) 133 N.J. 581, 600-603 (Coffman), and authority collected there.) In 

those jurisdictions, the plaintiff is “afforded the use of the presumption that he or she 

would have followed an adequate warning had one been provided, and . . . the defendant 

in order to rebut that presumption must produce evidence that such a warning would not 

have been heeded.” (Id. at p. 603.) Thus, use of this rebuttable heeding presumption 

shifts the “plaintiff’s burden of proof on the issue of causation as it relates to the absence 

of a warning.” (Ibid.) 

Appellants cannot rely on the heeding presumption to establish causation in this 

case for at least two reasons. First, as best we can determine, appellants never even 

mentioned this heeding presumption until after the trial was completed. Certainly, a jury 

instruction on the heeding presumption was neither given nor requested. Therefore, two 

principles bar appellants from raising this theory now: (1) a plaintiff cannot complain 

about the trial court’s failure to give an instruction he never requested; and (2) issues not 

raised in the trial court cannot be raised for the first time on appeal. (Willden v. 

Washington National Ins. Co. (1976) 18 Cal.3d 631, 636; Montez v. Ford Motor Co. 

(1980) 101 Cal.App.3d 315, 320; Jines v. Abarbanel (1978) 77 Cal.App.3d 702, 712-

713.) 

Applying these principles to preclude appellants from raising this new theory is 

particularly appropriate in light of the fact that the heeding presumption shifts the burden 

of proof; since appellants did not invoke this presumption at trial, Taylor-Dunn had no 

notice of or opportunity to rebut it. Furthermore, as a matter of fact, this heeding 

presumption cannot be used to support a finding by a jury that was never even instructed 

about the presumption.

Second, as the trial court stated in its JNOV order, California does not recognize 

the heeding presumption. (Huitt, supra, 188 Cal.App.4th at p. 1603; see also Dimond, 

supra, 65 Cal.App.3d at p. 185 & fn. 8 [finding no California case applying presumption 

and expressly declining to rely on a presumption to establish causation]; Motus v. Pfizer, 
23

Inc. (C.D. Cal. 2001) 196 F.Supp.2d 984, 992, fn. 5 [“the California Supreme Court has 

not applied and would not apply the presumption.”].) 

Appellants contend that a special jury instruction on the heeding presumption was 

not required because this “permissive presumption” is really nothing more than an 

inference that the jury was allowed to and allegedly did make. This “inference” was 

permissible, appellants contend, because it is implicitly recognized by California law. 

We will separately address the two flawed prongs of this erroneous argument.

First, the heeding presumption is not an inference. As explained earlier in our 

analysis, an inference is a deduction of fact that may logically and reasonably be drawn 

from evidence in the case. (Evid. Code, § 600; Collin, supra, 21 Cal.App.4th at p. 808.) 

Furthermore, an inference does not shift the burden of proof. (Dimond, supra, 65 

Cal.App.3d at p. 184.) By contrast, the heeding presumption does shift that burden. 

(Coffman, supra, 133 N.J. at p. 603.) 

Appellants maintain that there is no substantive distinction between a “permissive 

presumption” and an inference. (Citing People v. McCall (2004) 32 Cal.4th 175, 182.) 

This observation is beside the point because the heeding presumption is a mandatory 

presumption; it shifts the burden of proof. (Coffman, supra, 133 N.J. at pp. 600-603.) 

Furthermore, if the heeding presumption could somehow be re-packaged as an inference, 

then circumstantial evidence would be required to support it. As we have already 

explained above, the causation element of a failure to warn claim can be established 

inferentially with circumstantial evidence. (Dimond, supra, 65 Cal.App.3d 173.) Here, 

however, there is no circumstantial evidence in the trial record to support an inference of 

causation. Thus, what appellants ask now is to fill that evidentiary void by “recognizing” 

a presumption that would not only lessen their burden of proof but shift that burden to 

Taylor-Dunn. 

The second prong of appellants’ erroneous argument is that, although no 

California case has explicitly adopted the heeding presumption, this doctrine is “inherent 

in—indeed, is the premise of—California’s reasonable person test.” As we have already 

explained, appellants’ reasonable person test is not the standard that California applies in 
24

a strict product liability case. Under California law, the plaintiff alleging strict liability 

for a failure to warn must prove that the alleged failure to provide adequate warning was 

a substantial factor in bringing about the injury. (Huitt, supra, 188 Cal.App.4th at p. 

1604; Rutherford, supra, 16 Cal.4th at p. 968; Conte, supra, 168 Cal.App.4th at p. 112; 

CACI No. 1205.) 

Furthermore, the heeding presumption is not another label for a reasonable person 

test, as appellants contend; it is a doctrine which shifts the burden of proof regarding an 

essential element of a failure to warn claim. (Coffman, supra, 133 N.J. at pp. 600-603.) 

There may be sound policies for adopting that doctrine, but in view of the law discussed 

above, this appeal is not the proper process for seeking such a change.

III. DISPOSITION

The judgment is affirmed.

_________________________

Haerle, J.

We concur:

_________________________

Kline, P.J.

_________________________

Brick, J.*

* Judge of the Alameda County Superior Court, assigned by the Chief Justice 

pursuant to article VI, section 6 of the California Constitution.