Which auto insurers must contribute pro rata to motorcyclist's PIP benefits?

State Farm Mutual sued three other carriers in 2010 to force them to contribute to payment of an injured motorcyclist's PIP benefits.  The cyclist had stopped behind a line of cars on the freeway, when he was struck from the rear by a vehicle that could not stop.  State Farm insured the striking vehicle and sought contribution from the insurers of three cars that were also allegedly "involved" in the incident.

Because motorcyclists are rarely the cause of their own injuries when a vehicle is involved in a motorcycle collision, the no fault act was written to require involved car insurers to pay the cyclist's PIP benefits.  This case involved a dispute over what it meanst to be "involved."  It is clear from prior law that if the motorcyclist strikes an involved car, the car is "involved," even if the driver did nothing wrong.  Similarly, if the driver  of a car did something that contributed to the happening of the event, his car and his insurer are "involved." 

The more difficult issue is "passive involvement."  Prior cases have held that if a car is simply legally stopped at an intersection when it is "involved" in a collision-- without being actually struck by the biker or causing the event, that vehicle's insurer is not obligated to help pay PIP benefits.  In this case, the court held that there was too much factual ambiguity about which cars were struck by the biker to uphold the trial court's summary disposition of several insurers.  From the holding, it appears that the court was looking only to whether the BIKER struck ann insurer's car--and not to the question of whether his bike struck a particular car.