## Facts

- Shelly Sigler drove a certified pre-owned 1999 Honda Accord EX on Interstate 75 in Tennessee.
- Witness Terry Williams, driving 75–100 yards behind, estimated Sigler’s speed at about 70 mph and reported the car suddenly veered off the road without brake lights or turn signals.
- The vehicle went down an embankment, passed through a wire fence, and struck and uprooted a tree about six inches in diameter.
- The driver’s airbag did not deploy.
- Sigler alleged the airbag system was defective under the Tennessee Products Liability Act (TPLA) and that non-deployment caused or worsened her injuries, including seizure-related issues.
- Sigler relied on crash circumstances, her consumer expectations, manufacturer brochure statements about deployment in certain frontal crashes, and expert causation testimony.

## Issues

1. Whether a court may consider unsworn expert letters submitted by a defendant as summary-judgment evidence.
2. Whether the plaintiff presented sufficient admissible evidence to create genuine disputes of material fact on defect and causation under the TPLA, including by using consumer-expectation and circumstantial proof.

## Decision

- The Sixth Circuit reversed the grant of summary judgment for Honda and remanded.
- The court held the district court erred by considering Honda’s unsworn expert letters, which were inadmissible at the summary-judgment stage.
- The court held Sigler’s evidence, viewed favorably to her, was sufficient to permit a reasonable jury to find an airbag defect and causation.
- The court concluded the district court erred in excluding Sigler’s expert causation testimony.
- A partial dissent would have affirmed summary judgment for Honda.

## Legal Principles

- Summary judgment must be supported by evidence that can be presented in admissible form; unsworn expert letters or reports, standing alone, are inadmissible hearsay and cannot support summary judgment when properly objected to.
- Under the TPLA, a plaintiff may prove defect through consumer-expectation evidence: whether the product fell below the reasonable minimum safety expectations of an ordinary consumer with ordinary knowledge of the product’s characteristics.
- Tennessee products-liability claims may be supported by circumstantial evidence of defect and causation, including crash dynamics, physical damage, manufacturer statements, and admissible expert testimony.
- Where admissible evidence permits competing inferences about defect and causation, those disputes are for the jury and summary judgment is improper.

## Conclusion

The Sixth Circuit held that the district court improperly relied on inadmissible unsworn expert letters and that the plaintiff’s admissible consumer-expectation, circumstantial, and expert evidence created triable issues on whether an airbag defect existed and caused injury, requiring reversal and remand.


Sigler v. Am. Honda Motor Co., 532 F.3d 469 (6th Cir. 2008)