The plaintiff sued General Motors for injuries sustained in a car accident allegedly caused by defects in her 1982 Camaro. The Court of Appeal affirmed the judgment in favor of the plaintiff, but the trial court erred by giving an "ordinary consumer expectations" instruction in a complex case and should have granted GM's request for a special instruction explaining its correct theory of legal cause. However, both errors were harmless and did not warrant reversal of the Court of Appeal's judgment. The plaintiff alleged that GM was strictly liable for her ankle injuries resulting from a defective product. She claimed that the collapse of the Camaro's wheel caused the toe pan to crush violently upward against her feet due to a manufacturing defect in the weld attaching the lower control arm bracket to the frame. The plaintiff argued that the placement of the bracket and the configuration of the frame were defective designs. The evidence presented by both parties, including expert testimony in areas such as biomechanics, metallurgy, orthopedics, design engineering, and crash-test simulation, left room for debate about the exact impact angle, force, and extent of deformation of the toe pan. The plaintiff presented evidence in the form of crash tests and a real-world collision involving a similar Camaro to support her claim. Her experts argued that the deformation of the toe pan was necessary to produce enough force to fracture her ankles. The plaintiff's experts also highlighted the alternative design used by the Ford Mustang, which provided protection against unlimited rearward travel of the wheel in case of bracket assembly failure, unlike the Camaro's design.

The concurring judge agrees with the majority's conclusion but disagrees with the use of People v. Cahill as guidance. The judge believes that Cahill's opinion, which deemed coerced confessions to be harmless, is a cruel aberration in the law and casts doubt on the justice system's devotion to integrity. The judge thinks that citing Cahill for guidance reflects unfavorably on the current opinion's otherwise satisfactory analysis. The lower court's decision to rely on Cahill's opinion is erroneous.

The judge agrees with the majority's decision but disagrees with their conclusion that a certain error was harmless. The trial court did not allow General Motors' requested instruction on one of its primary defense theories, which was that any design defect could not have been a "substantial" or "contributing" cause of the plaintiff's "enhanced" injuries if they would have occurred even with a nondefective design. The proposed instruction was correct in form and substance, and if the force of the collision was so severe that the plaintiff's injuries would have occurred regardless of any "defect" in the vehicle's safety design, the defect cannot be considered a substantial factor or legal cause in bringing them about. General Motors presented substantial evidence that the force of the collision was the sole cause of the plaintiff's injuries, regardless of any defect. The trial court's refusal to instruct the jury based on this theory was a clear error. The proposed instruction was a correct statement of law and was amply supported by the evidence presented at trial.