16 I am also not persuaded that acceptance of the master tort theory is necessarily part of the ratio in Ramsay v Pigram or Stoneham v Lyons. The issue in Ramsay v Pigram was whether the respondent was estopped from asserting negligence by a police officer in the course of his duty. The respondent was injured when a government owned vehicle driven by the police officer collided with the respondent's vehicle. The police officer had sued the respondent for personal injuries arising out of the collision. The respondent was found to be negligent and the police officer was found not guilty of contributory negligence. Later, the respondent sued the appellant, as nominal defendant representing the government, for personal injuries suffered in the same collision. The Court held there was no issue estoppel because there was no privity of interest between the appellant (nominal defendant) and the police officer to entitle the appellant to rely on the findings in the police officer's action. The appellant's liability, if any, to the respondent, depended on the content of the duty owed by the owner of the car (the New South Wales Government) by virtue of s 16 of the Motor Vehicles (Third Party Insurance) Act 1942 (NSW) (Barwick CJ at 279, McTiernan J at 282 - 283, Taylor J at 285, with whom Kitto J agreed, and Windeyer J at 289). Section 16 provided that the driver of certain vehicles was deemed to be the agent of the owner acting within the scope of his authority for the purpose of enabling a third party injured by the negligence of the driver to recover against the insured owner. A principal is liable for loss or damage caused by the tort of his agent if the agent was acting within the scope of the agent's authority. It has not been established that a principal's liability for the agent's tort is "truly vicarious": Bowstead & FMB Reynolds Reynolds on Agency (17th ed) 2001 at par 8-177 to par 8-183. On my reading of the judgments in Ramsay, only Taylor J (and Kitto J) expressly characterises the statute as imposing vicarious liability on the owner of a vehicle for the acts or omissions of the driver. Three members of the Court (Barwick CJ, McTiernan and Windeyer JJ) also concluded that the issues in the two actions were not identical. They did so because of their view that the owner of the car owed an independent duty, which was not necessarily co-extensive with the personal duty of the driver, to persons injured by the negligence of the driver. However, that can occur regardless of the juristic basis for vicarious liability: see Twine v Bean's Express Ltd (1946) 62 TLR 458 (an employer was not liable for the negligence of his employee in the course of his duties). Barwick CJ's approval of Kitto J's judgment in Darling Island is arguably obiter.