What is the current state of the law on the immunity of a policy decision?

As noted in the above passage, the immunity of a policy decision from suit is contingent on the decision having been made in good faith. In other words, in order for a policy decision to give rise to tort liability, the plaintiff must establish that the decision is “so irrational or unreasonable as to constitute an improper exercise of government discretion” or “so patently unreasonable that it exceeds governmental discretion”: (Brown v. British Columbia (Minister of Transportation and Highways), 1994 CanLII 121 (SCC), [1994] 1 SCR 420 at para. 28)