Proximate cause jury instruction was further clarified by a Washington appellate court when the court reversed the asbestos defense verdict in Clevenger v. John Crane, Inc. In the case, plaintiff Era Clevenger alleged that her deceased husband’s forty-year history of occupational exposure to asbestos (in the Navy, as a city water department mechanic, and as a pipefitter) resulted in his death.

The only defendant remaining at trial was John Crane, Inc. The decedent died from either lung cancer or mesothelioma. At trial, experts disputed the type and location of the tumor. Each expert agreed the decedent’s smoking would have been a cause of lung cancer. But also agreed that asbestos could play a role in both forms of cancer. John Crane argued that plaintiff’s claim was specific to mesothelioma. Since there was no way of knowing whether the decedent had died of mesothelioma or lung cancer, the company could not be found liable. The jury found John Crane’s product was not reasonably safe, but that it was not the legal (or proximate) cause of the decedent’s injury. The plaintiff appealed, insisting the following jury instructions were misleading:

Jury Instruction: Proximate Cause

Under Washington law, juries are instructed that a plaintiff must prove that a defendant’s asbestos-containing product was a “substantial factor” in the plaintiff’s development of their alleged asbestos-related disease in order to establish proximate cause. In Clevenger, the jury instruction required the jury to find that John Crane’s product was “a substantial factor in bringing about [the decedent’s] mesothelioma,” and the plaintiff argued this instruction contained a critical error. Plaintiff argued that the instruction should not have been limited to just mesothelioma because its theory of the case was that an “asbestos-related disease” caused the decedent’s death. In its closing argument, defense argued that because mesothelioma had not been proven, proximate cause also had not been proven.

Jury Instruction: Lockwood Factors

Plaintiff also argued the Lockwood factors jury instruction was given in error. In the 1987 seminal asbestos case Lockwood v. AC&S  the Washington Supreme Court announced factors that should be considered in determining whether a plaintiff presented sufficient evidence establishing whether exposure to a particular asbestos-containing material was a substantial factor in the development of an asbestos-related injury.

There are seven factors under Lockwood:

    1. Proximity to an asbestos product when the exposure occurred.
    2. Expanse of work site where asbestos fibers were released.
    3. Extent of time of exposure to the product.
    4. Types of asbestos products exposed to.
    5. Ways in which the product was handled and used.
    6. Tendency of products to release asbestos fibers into the air depending on their form and method in which they were handled.
    7. Other potential sources of injury, such as medical causation.

In Clevenger, the trial judge permitted a common instruction, which lists these Lockwood factors. The plaintiff argued the Lockwood factors are only for the trial court to consider and not for a jury to consider. On appeal, the court decided that no case law prohibits a jury’s consideration of the Lockwood factors, but questioned whether these factors are appropriate for a jury instruction listing what the jury “should” consider in determining proximate cause. The court was concerned the jury instruction unduly restricted what the jury “may” consider under the circumstances of a particular case and did not endorse the jury instruction.

The appeals court vacated the defense judgment on proximate cause instruction grounds finding that the jury instructions submitted on proximate causation did not allow the plaintiff to argue its theory of the case. The court found it “troublesome when an instruction defining proximate cause undercuts a party’s theory as revealed by the pleadings, opening statement, and closing arguments.” Plaintiff’s theory of the case was that exposure to asbestos was a substantial factor in causing either mesothelioma or an asbestos-related lung cancer, and the proximate cause jury instruction only allowed the jury to consider plaintiff’s mesothelioma claim.

Attorneys practicing toxic tort litigation in Washington State should take care when submitting jury instructions in possible disputed diagnosis cases to ensure the jury instructions on proximate causation do not undercut the plaintiff’s theory of the case. Moreover, attorneys should be cautious in submitting Lockwood factors directly to a jury given appellate courts may find this prejudicial error in future cases. It remains to be seen if the case will be appealed further.