## Facts

- Alison Kimberly Pietrone rode as a passenger on a 1974 Honda CB 450 motorcycle driven by her husband.
- At an intersection, an oncoming automobile began a U-turn; the motorcycle moved right to avoid it.
- The car’s bumper struck the lower portion of Pietrone’s left leg, breaking it, but the impact did not overturn the motorcycle.
- After the fracture, Pietrone’s leg contacted the motorcycle’s exposed rear wheel spokes near the passenger foot pegs.
- As the wheel rotated, her foot was pulled into exposed openings around the shock absorber and chain-guard area, trapping her for several minutes.
- Pietrone sued Honda in strict products liability, alleging a design defect: an open, exposed, rotating rear wheel located close to the passenger foot pegs.
- A jury found for Pietrone, and judgment was entered in her favor; Honda appealed.

## Issues

1. Whether the evidence was sufficient to support a design-defect finding under California strict products liability, including consumer-expectations and/or risk–benefit theories.
2. Whether the evidence was sufficient to prove the alleged design feature was a proximate cause of Pietrone’s injuries.
3. Whether plaintiff’s counsel’s closing argument improperly referenced alternative designs not supported by evidence, requiring reversal.

## Decision

- The Court of Appeal affirmed the judgment for Pietrone.
- The court held the evidence supported a finding that the open, exposed, rotating rear wheel in close proximity to the passenger foot pegs was a proximate cause of the injury.
- Because causation by a design feature was shown, the burden shifted to Honda to justify the design under the risk–benefit test; the verdict implied Honda did not meet that burden.
- The court found no reversible error based on the challenged closing argument.

## Legal Principles

- A design defect may be proved by showing either (a) the product failed to perform as safely as an ordinary consumer would expect when used in an intended or reasonably foreseeable manner, or (b) the design’s risks outweigh its benefits.
- When a plaintiff shows that a specific design feature was a proximate cause of injury, the manufacturer bears the burden to prove, under the risk–benefit test, that the benefits of the design outweigh its dangers.
- A collision caused by a third party does not preclude strict-liability design-defect liability when the product’s design foreseeably contributes to or worsens the injury.
- Closing argument does not warrant reversal absent prejudice sufficient to undermine the verdict, particularly where the jury is properly instructed to distinguish argument from evidence.

## Conclusion

The court upheld a strict-liability verdict finding that a motorcycle’s exposed rear wheel assembly positioned near passenger foot pegs could be found defectively designed and causally related to severe entrapment injuries, and that once that causal link was shown the manufacturer bore the risk–benefit justification burden under California design-defect law.


Pietrone v. Am. Honda Motor Co., 189 Cal. App. 3d 1057 (Ct. App. 1987)