A taxi crashed into a telephone pole. The taxi's passenger commenced a negligence action against the taxi driver, properly serving the taxi driver with the summons and complaint. The taxi driver, being an independent contractor with no right to indemnity from the taxi's owner, turned the summons and complaint over to his insurance company. After trial, the jury returned a verdict in favor of the passenger, finding that the taxi driver's negligence was the sole cause of the crash. The passenger then commenced a second action, this time against the owner of the taxi. The owner also had no right of indemnity from the taxi driver. The passenger alleged that the taxi driver's negligence was the sole cause of the crash and that the owner was vicariously liable. The passenger immediately moved for partial summary judgment against the owner based on the finding of the taxi driver's negligence in the prior action. If the court denies the motion, what is the most likely reason