Issue by: Rachel R. Ostrander
Jae Kim v. Toyota Motor Corporation
California Supreme Court (August 27, 2018)

In Jae Kim v. Toyota Motor Corporation, 6 Cal. 5th 21 (2018), the California Supreme Court broke with 40+ years of court of appeal precedent barring manufacturers from using evidence of their compliance with industry custom and practice to prove their designs were not defective. The Court held that such evidence is not inadmissible, but neither is it categorically admissible.

In design defect cases, evidence of industry custom and practice compliance has historically been barred as irrelevant and prejudicial. However, in the Kim case, such evidence was deemed relevant to prove that the failure to include Vehicle Stability Control (VSC) as standard equipment in a 2005 Toyota Tundra light truck was not a design defect under the risk-benefit test.

Plaintiff William Jae Kim was severely injured after he lost control of his Toyota Tundra pickup truck and drove off an embankment. He brought a strict products liability suit against defendant Toyota Motor Corporation. At trial, he sought to exclude evidence of custom and practice, but his motion in limine was denied by the court. Toyota prevailed at trial, and the Court of Appeal affirmed the decision denying his motion.

The Supreme Court accepted discretionary review solely to determine whether admission of the custom evidence was reversible error, and affirmed, holding that the custom evidence was properly admitted. The Court declined to categorically opine that custom and practical evidence is always admissible. The Court instead required sound justification that depends on the evidence offered and the purpose for which it is offered, meaning that the admissibility of such evidence will need to be determined on a case by case basis.

Specifically, the Supreme Court held that evidence that a manufacturer’s design conforms with industry custom and practice is not relevant, and therefore not admissible, to show that the manufacturer acted reasonably in adopting a challenged design and therefore cannot be held liable. Under strict products liability law, a product may contain precisely the same safety features as other products on the market and still be defective. However, even though evidence of industry custom and practice cannot be dispositive of the issue, it may nevertheless be relevant to the strict products liability inquiry, including the jury’s evaluation of whether the product is as safely designed as it should be, considering the feasibility and cost of alternative designs. The Supreme Court agreed with the Court of Appeal that the evidence in this case was properly admitted for that limited purpose.

Attorneys practicing in the area of torts who regularly deal with design defect claims against private entities, may be able to overcome such claims where they can show that their clients’ were complying with an established custom and practice in the field. This is a stark contrast from past cases, and will impact lower courts’ future ruling on admissible evidence for trial and attorneys’ analysis of exposure for these kinds of claims. There will also undoubtedly be future cases flushing out the extent to which this kind of evidence is relevant.


The California Supreme has ruled that evidence of industry custom and practice compliance in design defect claims may be admissible. Attorneys who deal with design defect claims regularly will need to be abreast of the changing law in order to properly advise their clients about potential exposure based on this case and its progeny.

For a copy of the complete decision, see: Kim v. Toyota Motor Corp

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