Piner v. Superior Court

While driving to work one morning, William Piner (plaintiff) stopped his truck to let a pedestrian cross the street. While stopped, a vehicle driven by Billy Jones (defendant) hit Piner’s truck from behind. Although Piner telephoned his physician shortly afterward complaining of pain in his neck, back, arm, and head he was not able to obtain an appointment for several days. Later that same day, Piner was driving to lunch when the car ahead of him stopped to let some pedestrians cross the street. Piner stopped and was again hit from the rear by a vehicle driven by Cynthia Richardson (defendant). Piner again telephoned his physician complaining of similar pain that he experienced earlier that morning. Piner’s treating physician could not attribute any particular part of his injuries to one accident or the other. Piner filed suit against Jones and Richardson alleging indivisible injuries resulting from the successive impacts. All parties agreed that both collisions contributed to Piner’s total injuries but neither defendant could apportion fault. Piner moved for partial summary judgment arguing that in an indivisible injury case the defendants bear the burden of proving apportionment and if they cannot then they should be jointly and severally liable for the entire amount. The trial court denied Piner’s motion, but allowed Piner to file a special action to appeal the court’s decision with respect to the apportionment issue. The court of appeals declined to hear Piner’s case. The Arizona Supreme Court granted certiorari to determine which rule of liability applied in cases in which successive acts of negligence combined to produce separate but indivisible injuries.