High Court. If an officer detained an unlawful non-citizen "in the purported performance of a statutory duty to detain in conformity with the law as declared in a prior decision of this Court which has been held in a subsequent decision of this Court to have been erroneous", is that prior decision a defence to liability for the tort of false imprisonment?
The plaintiff was an unlawful non-citizen. An officer detained the plaintiff under s 189(1) of the Migration Act 1958 (Cth) contrary to NZYQ, in that his removal from Australia under s 198 had no real prospect of becoming practicable in the reasonably foreseeable future.
Some of the questions to the High Court (HCA) were as follows:
Question 1: Is the law declared by the Full Court of the High Court, in its original or appellate jurisdiction, in deciding a matter concerning the limits of governmental power "the law thereafter to be applied in accordance with the rules of precedent by all Australian courts of competent jurisdiction to determine the rights and obligations of parties to disputes concerning compliance with those limits and concerning legal consequences of non-compliance", even if declared in the High Court's original jurisdiction?
Question 2: Is it the "theory of our constitutional system being that invalid legislation "is, in legal contemplation, as inoperative as though it had never been passed" (such that the invalid law "confers no rights", "imposes no duties" and "affords no protection"), a subsequent declaration of constitutional invalidity can thereby reveal the action in retrospect to have exposed the executive government or its officers to civil liability at common law"? In other words, if a law is declared as invalid, is it invalid ab initio?
Question 3: If an officer detained an unlawful non-citizen "in the purported performance of a statutory duty to detain in conformity with the law as declared in a prior decision of this Court which has been held in a subsequent decision of this Court to have been erroneous", is that prior decision a defence to liability for the tort of false imprisonment?
Question 4: Can it be said that, "absent the propounded defence, the Commonwealth would be directly liable for the acts of the detaining officer in the purported performance of the statutory duty to detain imposed by ss 189(1) and 196(1)"?
Question 5: Does it follow from the axiom that the common law develops incrementally that the development of the common law excludes consequentialist reasoning?
The HCA answered those questions as follows: