Swanson v. The Marley-Wylain Co. CA2/1 ( 2021 )


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  • Filed 6/4/21 Swanson v. The Marley-Wylain Co. CA2/1
    NOT TO BE PUBLISHED IN THE OFFICIAL REPORTS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    has not been certified for publication or ordered published for purposes of rule 8.1115.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
    SECOND APPELLATE DISTRICT
    DIVISION ONE
    ROBERT SWANSON et al.,                                     B294181
    Plaintiffs and                                    (Los Angeles County
    Respondents,                                      Super. Ct. No. BC571451)
    v.
    THE MARLEY-WYLAIN
    COMPANY,
    Defendant and
    Appellant.
    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.
    ____________________________
    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 Marley-
    Wylain 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 Weil-
    McLain. 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).)
    1The Marley Company, LLC acquired Weil-McLain’s
    successor, Wylain, Inc., in 1980. In discovery responses, Marley-
    Wylain indicated that Weil-McLain is a division of The Marley-
    Wylain Company, which is a wholly owned subsidiary of The
    Marley Company, LLC.
    2Swanson 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.
    2
    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
    3
    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.
    4
    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.
    5
    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
    6
    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
    7
    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.”
    8
    (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.
    9
    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,
    10
    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 asbestos-
    containing 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. Owens-
    Illinois, 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
    11
    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.
    12
    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
    13
    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
    14
    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
    15
    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
    16
    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
    17
    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.
    NOT TO BE PUBLISHED
    CHANEY, J.
    We concur:
    ROTHSCHILD, P. J.
    BENDIX, J.
    18