Polston v. Boomershine Pontiac-GMC Truck, Inc.

In a defective-design suit against General Motors (defendant), Linda Polston (plaintiff) called mechanical engineer Murray Burnstine, who had no medical training, to testify her car's lack of crashworthiness caused her injuries; the district court allowed him to testify the car was not crashworthy but barred him from opining, to a reasonable medical certainty, that the lack of crashworthiness enhanced her injuries. The district court then granted GM's motion for a directed verdict, and Polston appealed.