Benn v. Thomas

Thomas (defendant) rear-ended Benn's vehicle, causing a bruised chest and broken ankle; Benn, who had preexisting coronary disease, diabetes, and a prior heart attack, died of a heart attack six days later. At trial, medical evidence was divided on whether the collision caused Benn's death, and Benn's estate (plaintiff) asked the court to instruct the jury on the eggshell plaintiff rule; instead, the trial court instructed the jury on ordinary substantial-factor causation, and the jury found Thomas's negligence was not the proximate cause of death. The court of appeals reversed, and the case reached the Iowa Supreme Court.