The Seventh Circuit recently held that a product liability plaintiff could not establish a prima facie case of defect without expert testimony, even where the plaintiff was relying solely on the “consumer-expectation” test for product defect. Show v. Ford Motor Co., Nos. 10-2428, 10-2637 (7th Cir. September 19, 2011). This is the first Illinois court to hold that a lay jury is not capable of relying solely on its own experience to decide whether a product fails to perform as safely as an ordinary consumer would expect. But the decision may be limited to complex products or a complex accident (in this case, the propensity of an automobile to rollover in a collision). Expert testimony is likely still not required where the accident and a product’s operation are within the understanding of an ordinary jury.

Plaintiffs in Show were riding in a Ford Explorer travelling through an intersection at approximately 30 m.p.h. Show, slip op. at 1. The Explorer was struck by another car near the left rear wheel and rolled over. Id. Plaintiffs alleged the Explorer was defectively designed because it rolled over. Id.

Plaintiffs relied on the consumer-expectation test. Id. at 2. Under that test, a design will be found defective where “the product failed to perform as safely as an ordinary consumer would expect when used in an intended or reasonably foreseeable manner.” Id.

Plaintiffs presented no expert testimony to support the allegation of design defect. Instead, Plaintiffs argued that expert testimony was unnecessary under the consumer-expectation test because “jurors, as consumers, can find in their own experience all of the evidence required for liability …” Id. at 2-3. The district court rejected plaintiffs’ argument and entered summary judgment for defendant. Id.

The Seventh Circuit affirmed, holding that expert testimony was required even under the consumer-expectation test. Id. at 7 (“If, as plaintiffs concede, it takes expert evidence to establish a complex product’s unreasonable dangerousness through a risk-utility approach, it also takes expert evidence to establish a complex product’s unreasonable dangerousness through a consumer-expectations approach.”)

The court noted that the issues were simply too complex for a jury to assess without expert testimony. First, the court stated that even the issue of “consumer expectations” was typically subject to expert testimony under federal law, noting that consumer surveys are often required in cases involving trademark disputes or allegedly deceptive loan advertising. Id. at 5. The court said expert testimony regarding consumer expectations was even more important in a product liability case, which involves more complex issues. Id. (“Jurors know less about product design than they know about what confuses people who buy toothpaste or borrow $10,000.”) The court also said this was particularly true when the product involved was complex, noting a study finding “most people can’t explain what makes a bicycle or toilet work. Cars are far more complex.” Id. at 8.

The court also noted that the consumer-expectation test had been modified by the Illinois Supreme Court in Mikolajczyk v. Ford Motor Co., 231 Ill. 2d 516 (2008), so that consumer expectations are not the only issue considered. Id. at 5-7. Instead, consumer expectations are just a single factor to consider, along with the risk of harm from a particular design, and the feasibility of alternative designs. Id.  

The court held that expert testimony on those other design-related issues is required. Id. at 10. Although all jurors are familiar with cars, that does not mean jurors can intelligently assess why a car was designed a certain way. Id. at 7. (“design options are the province of engineers. Jurors own cars, but people own lots of products without being able to explain (or even understand) the principles behind their construction and operation.”)

The court also stated that cases such as this one often involve complex accident mechanics and causation (e.g., what caused the rollover and what would have prevented it), which jurors cannot assess on their own. Id. at 7-9 (“Causation is a question about physics … Understanding requires some geometry and algebra; jurors’ unguided intuitions will not solve the equations.”)

It should be noted that the court’s discussion referred to the product at issue as a “complex” product, and noted the complexity of the accident mechanics. Id. at 3, 7, 8. See, e.g., Scoby v. Vulcan-Hart Corp., 211 Ill. App. 3d 106 (1991) (distinguishing between simple and complex products). Thus, an argument could be made that, even after Show, expert testimony may not be required if a “simple” product or “simple” accident mechanics are involved.

Finally, the court raised but declined to decide the issue of whether (in a federal case based on diversity) state or federal law controlled the need for expert testimony to establish a prima facie case of product defect. Id. at 4, 7. Thus, Show may be of limited value in Illinois state courts.