When must Utah courts give jury instructions on unapportionable preexisting injury damages? Robinson v. All-Star Delivery, Inc. Explained

In personal injury cases involving preexisting conditions, Utah courts face a recurring challenge: what happens when it’s impossible to separate damages caused by the defendant’s conduct from damages caused by the plaintiff’s prior injuries? The Utah Supreme Court’s decision in Robinson v. All-Star Delivery, Inc. clarifies when trial courts must instruct juries on this critical issue.

Background and Facts

Stephen Robinson had suffered severe injuries in a 1991 accident, including skull, hip, and femur fractures requiring nearly twenty surgeries and two years of hospitalization. In 1995, defendant Koew rear-ended Robinson while driving for All-Star Delivery. Robinson sued, claiming the second accident aggravated his preexisting injuries and caused new ones. Defendants admitted liability but disputed damages, with the case turning on conflicting expert testimony about whether Robinson’s ongoing pain stemmed from the 1991 or 1995 accident.

Key Legal Issues

The central issue was whether the trial court erred by refusing to give Robinson’s proposed jury instruction on apportionment of damages between preexisting conditions and the current accident. Robinson’s instruction would have told the jury that if they couldn’t reasonably apportion damages between the two accidents, they should hold defendants liable for all resulting injuries.

Court’s Analysis and Holding

The Supreme Court, applying correctness review to the jury instruction issue, held that the trial court erred. The court relied on its recent decision in Tingey v. Christensen and tort principles establishing that defendants must take plaintiffs as they find them. When conflicting expert testimony creates uncertainty about whether damages can be apportioned between a preexisting condition and the defendant’s tort, courts must give the requested instruction. The court found this error prejudicial because the jury might have awarded more damages under proper instruction.

Practice Implications

This decision provides important guidance for Utah practitioners handling preexisting condition cases. Plaintiffs should request apportionment instructions when expert testimony conflicts about causation, but they must present evidence that actually raises the possibility that damages cannot be reasonably separated. The court also addressed evidentiary issues, holding that evidence of plaintiff’s disability benefits should generally be excluded as more prejudicial than probative, while evidence that the defendant wasn’t injured in the accident remains admissible as relevant to accident severity.