What is the difference between a policy decision and its operational implementation?

At the end of the day this case turns on what was referred to as the policy versus operational distinction. For our purposes this is best set out in Just v. British Columbia (supra) at 705: The need for distinguishing between a governmental policy decision and its operational implementation is thus clear. True policy decisions should be exempt from tortious claims so that governments are not restricted in making decisions based upon social, political or economic factors. However, the implementation of those decisions may well be subject to claims in tort. What guidelines are there to assist courts in differentiating between policy and operation?