Filed 6/4/21; Certified for Publication 6/24/21 (order attached)

IN THE COURT OF APPEAL OF THE STATE OF CALIFORNIA

SECOND APPELLATE DISTRICT

DIVISION ONE

ROBERT SWANSON et al.,

Plaintiffs and 

 Respondents,

v.

THE MARLEY-WYLAIN 

COMPANY,

Defendant and 

 Appellant.

 B294181

 (Los Angeles County

 Super. Ct. No. BC571451)

APPEAL from a judgment of the Superior Court of Los 

Angeles County, C. Edward Simpson, Judge. Reversed and 

remanded.

Horvitz & Levy, Curt Cutting, Dean A. Bochner; Manning 

Gross & Massenburg and David M. Glaspy for Defendant and 

Appellant.

Waters Kraus & Paul and Michael B. Gurien for Plaintiffs 

and Respondents.

____________________________
2

Robert Swanson worked as a plumber at Thomas Plumbing

& Heating in Michigan from 1969 to 1976. During that time, he 

was exposed to asbestos when working with boilers manufactured 

by Weil-McLain Company, Inc. (now a division of The MarleyWylain Company (MW)).1 Swanson’s occupational asbestos 

exposure continued at other jobsites until he retired in 2005, 

though after 1976 he was never again exposed to asbestos 

supplied by or contained in products manufactured by WeilMcLain. Swanson was diagnosed with mesothelioma in 2014. In 

2015, he filed suit against a number of defendants, including 

MW, for his injuries.2

Swanson’s exposure to asbestos supplied by or in products 

manufactured by Weil-McLain occurred entirely in Michigan. On 

that basis, MW moved the trial court for an order that Michigan 

law applied to Swanson’s claims against MW. The trial court 

denied MW’s motion. MW sought, and we granted, a peremptory 

writ of mandate ordering the trial court to vacate its order 

denying MW’s motion and to issue a new order granting the 

motion. (The Marley-Wylain Co. v. Superior Court (Mar. 24, 

2016, B267711) at p. 8 [nonpub. opn.] (MW I).)

1 The Marley Company, LLC acquired Weil-McLain’s 

successor, Wylain, Inc., in 1980. In discovery responses, MarleyWylain indicated that Weil-McLain is a division of The MarleyWylain Company, which is a wholly owned subsidiary of The 

Marley Company, LLC. 

2 Swanson died on March 2, 2016. In an amended 

complaint following Swanson’s death, his son, Shawn, identified 

himself as Swanson’s successor-in-interest and added wrongful 

death allegations. 
3

Swanson’s claims against MW were tried to a jury in 

August 2018. The jury concluded that Weil-McLain was 

negligent and that its negligence was a proximate cause of 

Swanson’s injuries. Based on the jury’s verdict, the trial court 

entered judgment for Swanson against MW for $5,489,688.68. 

The trial court denied post-judgment motions for judgment 

notwithstanding the verdict and new trial.

MW contends that the judgment must be reversed because 

the record contains insufficient evidence under Michigan law of a 

causal link between Swanson’s exposure to asbestos supplied by 

Weil-McLain and Swanson’s injury. MW alternatively contends 

that it is entitled to a new trial based on trial court error 

instructing the jury regarding causation under Michigan law. 

Finally, MW contends that the trial court improperly precluded 

evidence that would have impeached Swanson’s testimony 

regarding his exposure to asbestos from Weil-McLain’s products.

The evidence of causation presented at trial would have 

been sufficient under Michigan law to support the jury’s verdict. 

But the trial court’s instructions to the jury regarding causation 

reflected California law, not Michigan law. Because we conclude 

that the trial court improperly instructed the jury on Michigan 

law and that the error was prejudicial, we will reverse the 

judgment and remand to the trial court for retrial. Based on our 

conclusion that the judgment must be reversed, we do not reach 

MW’s contention regarding the admissibility of precluded 

evidence. 

BACKGROUND

Robert Swanson was born in 1947 in Ishpeming, Michigan.

Swanson enlisted in the United States Navy on his 17th birthday

in November 1964. According to trial testimony, Swanson was
4

probably first exposed to asbestos during a two-year naval 

assignment beginning in November 1966 aboard the U.S.S.

Theodore E. Chandler.

Swanson returned to Michigan after his discharge from the 

Navy and began working as a plumber at Thomas Plumbing & 

Heating (Thomas) in early 1969. Swanson’s work included 

installing and servicing heating and plumbing systems in both 

new constructions and existing homes and other buildings. 

Swanson’s work at Thomas included installing and maintaining 

boilers Weil-McLain manufactured. At his deposition, Swanson 

estimated that he installed more than 20 (and possibly as many 

as 100) Weil-McLain boilers (all but one in residences) during his 

time at Thomas. 

Weil-McLain manufactures boilers that provide “comfort 

heat”—heat at a relatively consistent temperature—for buildings 

of different sizes. All but one of the Weil-McLain boilers Swanson 

installed were factory-assembled “packaged boilers.” Swanson 

testified that during these installations he was exposed to 

asbestos supplied by Weil-McLain in the form of a powder he had 

to mix with water to make a paste to seal the area between a

boiler’s exhaust pipe and the chimney into which it was routed. 

When he serviced a boiler, Swanson testified that he was 

exposed to asbestos when he removed asbestos-containing 

gaskets on the boilers. To remove the gaskets, Swanson 

sometimes used a putty knife and a hand wire brush, and the 

process generated dust that Swanson inhaled. 

Swanson testified that he installed one Weil-McLain boiler 

that was not a packaged boiler—at Michigamme High School in 

the early 1970s. As part of that installation, Swanson testified 

that he handled asbestos rope and gaskets containing asbestos. 
5

Although Swanson’s work with Weil-McLain boilers ended 

when he left Thomas, Swanson’s exposure to asbestos—even 

while he was at Thomas—was not limited to Weil-McLain boilers. 

Swanson performed maintenance work on other boiler brands, 

and testified that he was exposed to asbestos as part of that 

work. He also worked around drywallers, who removed and 

installed drywall and insulation. The joint compound that 

drywall workers sanded contained asbestos, and when asked 

what the “dustiest” part of his job at Thomas was, Swanson 

testified that it was “[w]hen the drywallers were cleaning up and 

sanding their drywall compound.” Swanson was also exposed to 

asbestos in drywall joint compound that he applied and sanded in 

a home he built in 1974. 

Swanson left Thomas in 1976. From 1976 to his retirement 

in 2005, Swanson worked as a pipefitter. From 1976 to 1979, 

Swanson worked at mining operations in Michigan. Swanson did 

not believe he had been exposed to asbestos on the job from 1976 

to 1979. 

Swanson moved to California in 1979 and continued 

working as a pipefitter, initially for a construction company and 

later for a heating and air conditioning company called Air 

Conditioning Company, Inc. (ACCO). ACCO installed heating 

and air conditioning systems in commercial buildings. Swanson 

testified that he was exposed to asbestos as part of his work at 

ACCO. 

Swanson was diagnosed with mesothelioma in 2014. In 

February 2015, Swanson filed his original complaint against MW 

and several other defendants, alleging under California law that 

asbestos in the defendants’ products, including Weil-McLain’s 

boilers, had caused Swanson’s mesothelioma. 
6

In August 2015, MW moved the trial court for an order

declaring that, because Swanson’s exposure to asbestos from 

Weil-McLain products occurred entirely within the State of 

Michigan, Michigan law applied to Swanson’s claims against 

MW. The trial court denied MW’s motion. MW petitioned this 

court for a writ of mandate ordering the trial court to vacate its 

order and issue an order granting MW’s motion. We granted 

MW’s petition for writ of mandate and ordered the trial court to 

apply Michigan law to Swanson’s claims against MW. (MW I, 

supra, B267711 at p. 8.) 

Swanson died on March 2, 2016. Swanson’s son, Shawn, 

identified himself as Swanson’s successor-in-interest and 

amended the complaint to include his own allegations against 

Weil-McLain for his father’s wrongful death.

The matter was tried to a jury in August 2018; MW was the 

only remaining defendant. After trial, the jury concluded that 

Weil-McLain was negligent and that Weil-McLain’s negligence 

was a proximate cause of Swanson’s mesothelioma. Based on the 

jury’s verdict, the trial court entered judgment for Swanson 

against MW for $5,489,688.68. 

MW filed, and the trial court denied, motions for a new 

trial and for judgment notwithstanding the verdict. 

MW filed a timely notice of appeal. 

DISCUSSION

MW contends we should reverse the trial court’s judgment 

on three bases. MW’s primary contention is that Michigan law 

applies to Swanson’s negligence claim against MW. MW argues 

that under Michigan law, which MW contends requires evidence 

of “but for” factual causation, the trial evidence regarding the 

causal link between his exposure to asbestos from Weil-McLain 
7

products and his mesothelioma is insufficient to support the 

jury’s verdict. MW also contends that the trial court committed 

instructional error by improperly instructing the jury regarding

causation. Finally, MW contends the trial court committed 

prejudicial error by excluding admissible evidence that would 

have impeached Swanson’s testimony regarding his exposure to 

asbestos from Weil-McLain products.

As we explain below, we agree that Michigan law applies. 

Based on what we understand Michigan law to require, the 

evidence adduced at trial could support the jury’s verdict had the 

jury been properly instructed. Nevertheless, the record 

establishes that the jury was instructed on causation based on 

the California standard, not Michigan’s. We will therefore 

remand the case to the trial court for a new trial. Because MW is 

entitled to reversal based on this contention, we do not reach 

MW’s remaining contention.

A. Application of Michigan Law

In August 2015, MW moved the trial court for an order to 

apply Michigan law to Swanson’s claims; the trial court denied 

the motion. (MW I, supra, B267711 at p. 2.) MW petitioned this 

court for a writ of mandate ordering the trial court to vacate its 

order denying MW’s motion and enter a new order granting the 

motion. (Id. at p. 8.) We granted MW’s petition. (Ibid.)

In our opinion granting MW’s petition, we explained that 

“Michigan law, and not California law, applies where plaintiff 

Robert Swanson’s claims against [MW] arose in Michigan, where 

Swanson resided and where he was exposed to asbestos.” (MW I, 

supra, B267711 at p. 2.) We “direct[ed] the superior court to 

reverse its order denying the motion of [MW] to apply Michigan 
8

law to Swanson’s claims and to grant the motion on Swanson’s 

claims against [MW] only.” (Ibid., fn. omitted.)

MW contends that our opinion in MW I is the law of the 

case and established that Michigan law applies to Swanson’s 

claims against MW. “The law of the case doctrine states that 

when, in deciding an appeal, an appellate court ‘states in its 

opinion a principle or rule of law necessary to the decision, that 

principle or rule becomes the law of the case and must be adhered 

to throughout its subsequent progress . . . .’ ” (Kowis v. Howard

(1992) 3 Cal.4th 888, 892-893.) The doctrine does not extend to 

summary denials of writ petitions. (Id. at p. 894.) But when “the 

matter is fully briefed, there is an opportunity for oral argument, 

and the cause is decided by a written opinion[,] [t]he resultant 

holding establishes law of the case upon a later appeal from the 

final judgment.” (Ibid.)

Swanson responds that neither MW’s trial court motion, 

MW’s writ petition, nor our opinion granting MW’s writ petition 

specifically mentions the application of Michigan law on 

causation in negligence causes of action to Swanson’s claims. 

Because nobody specifically mentioned causation, Swanson 

argues, our prior opinion is not the law of the case regarding this 

particular element of a negligence cause of action, and therefore 

California law should apply. Choice of law, Swanson contends, 

is analyzed on an issue-by-issue basis. MW’s failure to request 

in its motion to apply Michigan law to Swanson’s claims that the 

trial court apply Michigan causation law to Swanson’s

negligence cause of action is fatal to MW’s argument, according 

to Swanson.

Swanson is correct that California courts examine choice of 

law questions “with regard to the particular issue in question.” 
9

(See McCann v. Foster Wheeler LLC (2010) 48 Cal.4th 68, 88, 

quoting Kearney v. Salomon Smith Barney (2006) 39 Cal.4th 95, 

107.) Swanson extends that contention, however, to an 

untenable end—that the law of different states may govern 

different elements of a single cause of action in cases pending in 

California state courts; that each element constitutes a separate 

issue for purposes of a choice of law determination. We are 

aware of no authority that would support that proposition, and 

we reject that argument.

There is nothing in our prior opinion that limits its 

application to the specific distinctions between California and 

Michigan law that drove our analysis and conclusion. MW’s 

motion was premised on the fact that Swanson’s exposure to 

Weil-McLain products occurred entirely in Michigan, that there 

are “material differences in California and Michigan product 

liability and damages laws,” that Michigan’s interest in applying 

its own law to Swanson’s claims against Weil-McLain is superior 

to California’s interest, and that Michigan’s interests would be 

more impaired than California’s if California substantive law 

applied to Swanson’s claims against MW. MW used examples of 

differences between California and Michigan product liability 

and damages laws. Those examples demonstrated that there 

were differences between California and Michigan law that 

warranted a judicial determination regarding which state’s law 

should apply to Swanson’s claims. But MW’s moving papers and 

request for writ relief and our opinion granting MW’s writ 

petition all discussed the issue as whether Michigan law should 

govern Swanson’s substantive claims against MW, not whether 

Michigan law governed specific elements of individual causes of 

action in Swanson’s complaint.
10

We recognize that Swanson opposed MW’s motion and writ 

petition by arguing about whether there were specific differences 

in various limited aspects of Michigan and California law. But 

Swanson’s efforts to limit the relief requested or granted did not

change the relief MW requested or that we granted.

The issue in MW’s motion to apply Michigan law to 

Swanson’s claims against MW and the subsequent writ petition 

was whether Michigan law applied to Swanson’s claims against 

MW. It was not whether Michigan law governed specific 

elements of various causes of action. And our opinion in MW I

preclusively established for purposes of the litigation in the trial 

court and this appeal that Michigan law governs Swanson’s 

claims against MW.

B. Causation Under Michigan Law

Swanson contends that causation in asbestos cases is the 

same in California and Michigan. MW contends it is different; 

that factual causation (as distinguished from legal causation) in 

California is governed by an “every exposure” theory, but 

Michigan requires evidence of “but for” causation in all 

negligence actions and that asbestos cases are no exception. We

do not agree with either Swanson or MW.

“ ‘The elements of an action for negligence [in Michigan] 

are (i) duty, (ii) general standard of care, (iii) specific standard of 

care, (iv) cause in fact, (v) legal or proximate cause, and (vi) 

damage.’ ” (Ray v. Swager (2017) 501 Mich. 52, 63, fn. 13, italics 

added, quoting Moning v. Alfono (1977) 400 Mich. 425, 437.) 

“Proximate cause is an essential element of a negligence claim. It 

‘involves examining the foreseeability of consequences, and 

whether a defendant should be held legally responsible for such 

consequences.’ Proximate cause is distinct from cause in fact, 
11

also known as factual causation, which ‘requires showing that 

“but for” the defendant’s actions, the plaintiff’s injury would not 

have occurred.’ ” (Ray, at p. 63, fns. omitted.)

In California, “[i]n the context of a cause of action for 

asbestos-related latent injuries, the plaintiff must first establish 

some threshold exposure to the defendant’s defective asbestoscontaining products, and must further establish in reasonable 

medical probability that a particular exposure or series of 

exposures was a ‘legal cause’ of his injury, i.e., a substantial 

factor in bringing about the injury.” (Rutherford v. OwensIllinois, Inc. (1997) 16 Cal.4th 953, 982, original italics, fns. 

omitted (Rutherford).) “[T]he plaintiff may meet the burden of 

proving that exposure to defendant’s product was a substantial 

factor causing the illness by showing that in reasonable medical 

probability it was a substantial factor contributing to the 

plaintiff’s or decedent’s risk of developing cancer.” (Ibid., italics 

added.)

Michigan asbestos-specific negligence cases have not made 

as distinct a division between proximate and factual causation as 

other Michigan negligence cases that have expressly considered 

the distinction between proximate and factual cause. 

Nevertheless, Michigan’s asbestos cases instruct that “[t]here 

may be more than one proximate cause of an injury” such that 

multiple “causes frequently operate concurrently so that [they] 

constitute a direct proximate cause of the resulting harm.” (Allen 

v. Owens-Corning Fiberglas Corp. (1997) 225 Mich.App. 397, 

401.) “[A] defendant cannot escape liability for its negligent 

conduct simply because the negligence of others may also have 

contributed to the injury suffered by a plaintiff. When a number 

of factors contribute to produce an injury, one actor’s negligence 
12

will be considered a proximate cause of the harm if it was a 

substantial factor in producing the injury.” (Id. at pp. 401-402; 

accord Brisboy v. Fibreboard Corp. (1988) 429 Mich. 540, 547

(Brisboy).)

That does not lead us, however, to conclude—as Swanson 

would have us—that Michigan has adopted California’s 

Rutherford causation standard. A substantial factor contributing 

to an increased risk of a plaintiff’s injury is not the same thing as 

a substantial factor in producing the injury. (See Davis v. 

Honeywell Internat. Inc. (2016) 245 Cal.App.4th 477, 493.) 

Consistent with our understanding of Michigan law, we conclude 

that to establish causation under Michigan law in a negligence 

cause of action for asbestos-related latent injuries, a plaintiff 

must establish and a jury must conclude that the defendant’s 

actions were a substantial factor in producing the plaintiff’s 

injuries, and not merely in increasing the risk that the plaintiff 

would suffer the injury.

1. Sufficiency of Swanson’s Causation Evidence

The record reflects that Swanson tried his case to the jury 

as though the California causation standard was the proper 

standard.

Swanson’s experts told the jury that “asbestos is the only 

known environmental cause of mesothelioma. If a person has a 

diagnosis of mesothelioma and an established asbestos exposure, 

there’s no reason to talk about any other cause.” Dr. Arnold 

Brody, an experimental pathologist and cell biologist, explained 

that mesothelioma is a “dose response” disease, “meaning the 

more a person’s exposed to [asbestos], the more likely they are to 

get [the] disease.” Dr. Brody told the jury that “[t]hat doesn’t 

mean you have to be exposed to huge amounts to get the disease. 
13

It means the more you’re exposed to it, the more likely you are. 

But some people have had really relatively low exposures and get 

mesothelioma. It all depends on susceptibility.” But Dr. Brody 

recognized that there are threshold levels of exposure below 

which a person will not develop mesothelioma.

Perry Gottesfeld, an industrial hygienist, testified that he 

was not familiar with “a minimum safe dose of exposure to 

asbestos.” Gottesfeld testified that exposures as high as 

Swanson’s likely exposure from the materials he was exposed to 

working on Weil-McLain boilers “would increase one’s risk of 

coming down with mesothelioma.” 

Dr. Barry Horn, a board-certified pulmonologist and 

critical-care specialist testified that Swanson’s mesothelioma was 

caused by his exposure to asbestos. Swanson “was previously 

exposed to asbestos because of multiple jobs that he had,” Dr. 

Horn testified. “His risk of developing mesothelioma was dose 

dependent. He had varying exposures. It was those exposures to 

asbestos that ultimately resulted in him developing 

mesothelioma.” Dr. Horn’s testimony made clear that 

mesothelioma “is a dose dependent disease.” “The more exposure 

you have,” he told the jury, “the greater your risk.” Dr. Horn 

testified that Swanson’s exposure to asbestos while he was 

onboard a Navy ship contributed to him getting mesothelioma, 

and that Swanson “had other exposures to asbestos in the course 

of his career working as a plumber. And they all contributed to 

his risk for the development of mesothelioma. The Navy 

exposure contributed to his risk, and his subsequent exposure to 

occur as a plumber also contributed to his risk.” Dr. Horn told 

the jury that neither he, nor anyone else, could tell the jury the 

“tipping point,” or “what caused [Swanson] finally to tip over to 
14

getting . . . asbestos-caused mesothelioma.” Dr. Horn’s testimony 

continued in the same vein. He testified to the jury consistently 

that every one of Swanson’s exposures to asbestos “contributed to 

his risk because it’s a dose dependent disease. So, the more 

exposures he had, the more likely he would develop 

mesothelioma.” 

The record details Swanson’s exposure to asbestos from the 

time he was a teenager in the Navy in the late 1960s until he 

retired from being a pipefitter in California in 2005. A significant 

part of that, according to trial testimony, was his exposure to 

asbestos from Weil-McLain boilers and related products from 

1969 to 1976.

Nevertheless, in one question and answer, the record

discloses evidence that would have been sufficient to support the 

jury’s verdict had the jury been properly instructed on causation. 

Swanson’s counsel asked Dr. Horn whether it was his opinion 

that Swanson’s “work with Weil-McLain boilers was a substantial 

factor, proximate cause” of Swanson’s mesothelioma. Dr. Horn 

replied “yes.” An expert witness in California may give testimony 

that “ ‘embraces the ultimate issue to be decided by the trier of 

fact.’ ” (Summers v. A.L. Gilbert Co. (1999) 69 Cal.App.4th 1155, 

1178, quoting Evid. Code, § 805.)

2. Instructional Error

MW contends that the trial court erroneously instructed 

the jury regarding causation in two different ways. First, MW 

contends that the trial court erred by not giving a special 

instruction that MW requested, which would have instructed the 

jury that Swanson had to prove that “but for” Weil-McLain’s 

actions, Swanson would not have been injured. Second, MW 

contends that the instruction the trial court did give was based 
15

on California’s causation standard, which, as explored above, is 

different from and more lax than Michigan’s causation standard. 

Based on our conclusion regarding Michigan’s causation standard 

that we explored above, we reject MW’s first contention. But we 

agree with MW’s second contention.

We review a trial court’s instructions to the jury de novo. 

(Alamo v. Practice Management Information Corp. (2013) 219 

Cal.App.4th 466, 475.) In determining if any error was 

prejudicial, we consider whether it is “reasonably probable” that 

the party asserting error “would have obtained a more favorable 

result in its absence.” (Soule v. General Motors Corp. (1994) 8 

Cal.4th 548, 570 (Soule).)

a. MW’s Requested Special Instruction

MW requested that the trial court specially instruct the 

jury regarding causation. MW’s requested special instruction 

included the following language: “Asbestos exposure from a 

defendant’s product can be considered a substantial factor in 

causing a plaintiff injury if both (1) it is established that 

plaintiff’s injury would not have happened but for his exposure to 

asbestos from defendant’s product and (2) that the asbestos 

exposure from defendant’s product had such an effect in 

producing the plaintiff’s injury that a reasonable person would 

conclude that this exposure was responsible for causing plaintiff’s 

injury.”

“A party in a civil case is, upon request, entitled to correct 

jury instructions on every theory of the case that is supported by 

substantial evidence. [Citation.] ‘It is elementary that a court 

may refuse a party’s request for a jury instruction that misstates 

the law. “A trial court has no duty to modify or edit an 

instruction offered by either side in a civil case. If the instruction 
16

is incomplete or erroneous the trial judge may, as he did here, 

properly refuse it.” ’ ” (Olive v. General Nutrition Centers, Inc.

(2018) 30 Cal.App.5th 804, 813.)

As we explored above, we do not agree with MW’s 

contention that Michigan law requires a plaintiff to prove “but 

for” causation, rather that the defendant’s actions were a 

substantial factor in producing the plaintiff’s injury. Because the 

jury instruction would have erroneously instructed the jury, the 

trial court correctly refused the instruction.

b. The Trial Court’s Instruction

The trial court’s instruction to the jury contained the 

following language: “[A] proximate cause in causing harm is a 

factor that . . . a reasonable person would consider to have 

contributed to the harm. It does not have to be the only cause of 

harm. Plaintiff may prove that exposure to asbestos from . . . 

Weil-McLain’s asbestos-containing product was a proximate 

cause in causing decedent’s illness by showing through expert 

testimony that there was a . . . reasonable medical probability 

that the exposure was a proximate cause contributing to . . . 

decedent’s risk of developing cancer.”

The trial court’s instruction reflects the law on causation in 

California as articulated in the Rutherford case. In that case, our 

Supreme Court explained that under California law, a plaintiff 

“may meet the burden of proving that exposure to defendant’s 

product was a substantial factor causing the illness by showing 

that in reasonable medical probability it was a substantial factor 

contributing to the plaintiff’s or decedent’s risk of developing 

cancer.” (Rutherford, supra, 16 Cal.4th at p. 982, italics added.) 

The language in the trial court’s instruction, then, was lifted 

directly from the Rutherford case and expressly instructed the 
17

jury to consider the question using the California standard, 

which we have explained is less stringent than the Michigan 

standard.

The trial court’s instruction was incorrect.

Instructional error in a civil case, however, “generally does 

not warrant reversal unless there is a reasonable probability that 

in the absence of the error, a result more favorable to the 

appealing party would have been reached.” (Soule, supra, 8 

Cal.4th at p. 574.) “That assessment, in turn, requires evaluation 

of several factors, including the evidence, counsel’s arguments, 

the effect of other instructions, and any indication by the jury 

itself that it was misled.” (Ibid.)

As we have discussed, and as the respondent’s briefing in 

this court acknowledges, Swanson tried this case on the theory 

that California’s causation standard applied to the negligence 

cause of action the jury heard. At the very least, Swanson 

argued, California and Michigan law on the question were 

identical, and instructing the jury on California law was

appropriate. We have rejected that argument, but it highlights 

that the overwhelming thrust of Swanson’s case in the trial court 

was geared toward California’s causation standard, and not any 

standard that would require a different or more stringent 

quantum or type of evidence. And during argument to the jury, 

Swanson argued relentlessly about Swanson’s “increased . . . risk

of developing mesothelioma” based on exposure to Weil-McLain 

products.

The jury in this matter was repeatedly told that any 

exposure to asbestos was sufficient to increase a person’s risk of 

mesothelioma, and that to find MW responsible under a 

negligence theory, Swanson needed only demonstrate that 
18

exposure to asbestos in Weil-McLain boilers had increased his 

risk of contracting the disease. Had the jury been properly 

instructed, we believe it is reasonably probable that a jury could 

have concluded that Swanson had not met his burden of 

demonstrating the causal connection Michigan law requires—

that the exposure was a substantial factor in producing the 

injury, rather than in merely increasing the risk of the injury.

DISPOSITION

The judgment is reversed. The matter is remanded to the 

trial court for a new trial. Appellant is awarded costs on appeal.

CHANEY, J.

We concur:

ROTHSCHILD, P. J.

BENDIX, J.
Filed 6/24/21

CERTIFIED FOR PUBLICATION

IN THE COURT OF APPEAL OF THE STATE OF CALIFORNIA

SECOND APPELLATE DISTRICT

DIVISION ONE

ROBERT SWANSON et al.,

Plaintiffs and 

 Respondents,

v.

THE MARLEY-WYLAIN 

COMPANY,

Defendant and 

 Appellant.

 B294181

 (Los Angeles County

 Super. Ct. No. BC571451)

 ORDER CERTIFYING 

 OPINION FOR 

 PUBLICATION

 [NO CHANGE IN

 JUDGMENT]

The opinion in the above-entitled matter filed on June 4, 

2021, was not certified for publication in the Official Reports. For 

good cause it now appears that the opinion should be published in 

the Official Reports and it is so ordered.

There is no change in judgment.

____________________________________________________________

ROTHSCHILD, P. J. CHANEY, J. BENDIX, J.