Diaz (defendant) was driving an ambulance that belonged to Robert Wood Johnson University Hospital at Hamilton (RWJ) (defendant) when he hit Panniel’s (plaintiff) car. Panniel’s foot was cut, and she was diagnosed with new onset diabetes. Panniel’s toes were amputated. Later, Panniel was diagnosed with carpal tunnel syndrome. Panniel filed a claim for personal injury protection (PIP) medical benefits with her insurance provider, New Jersey Manufacturers Insurance Company (NJM) (defendant). Panniel also filed a tort lawsuit against the defendants in New Jersey Superior Court. NJM contested Panniel’s PIP claims on the ground that the injuries were not the result of the car accident, and the case was submitted to arbitration. NJM also insured Diaz and RJW. In the arbitration between Panniel and NJM, the parties engaged in significant discovery and put on substantial evidence related to the causal link between Panniel’s injuries and the accident. The arbitrator examined medical records. Panniel’s doctor testified and was cross-examined, and NJM submitted a written report from its own expert. The arbitrator concluded that Panniel’s foot injury and amputation were “causally related” to the accident and ordered NJM to pay the medical benefits under the policy, but that the carpal tunnel was not the result of the accident. Panniel then filed a motion in the trial court, seeking partial summary judgment on the issue of causation. Panniel argued that the defendants were collaterally estopped from relitigating the issue. Panniel agreed to waive damages above the defendants’ policy limits with NJM. Diaz and RJW objected to the motion on the ground that they were not parties to the arbitration action and should not be bound.