In an action arising from personal injuries arising from a motor vehicle accident, the defendant vehicle owner brought a motion for summary judgment for a determination as to whether she was the actual owner and the registered owner of the vehicle driven by her son, the defendant driver, at the time of the accident. The parties agreed at the time of the motion that if the defendant owner was found to be the owner of the vehicle, her insurer would respond to the claim and the plaintiff’s own insurer (whose policy had the same limit as the defendant owner’s policy) could be released from the action. The motion judge held that the defendant owner was the actual owner of the vehicle and dismissed the action as against the plaintiff’s insurer. The defendant owner then moved to withdraw her agreement that she would be vicariously liable for the losses caused by her son’s driving under the Highway Traffic Act if she were found to be the owner of the truck. The motion judge rejected this request and the defendant owner appealed. The Court of Appeal upheld the motion judge’s holding that the defendant owner’s admission made during argument could not be withdrawn. The Court of Appeal reasoned that if the appeal were successful, the defendant owner’s insurer would not be liable to pay the loss and the plaintiff’s own insurer, having obtained dismissal from the action, would also not be liable to pay. The outcome would prejudice the other parties in the action in a manner which could not be remedied by an order for costs. The interests of justice did not require that the defendant owner be permitted to withdraw her agreement.