In a concurring judgment in Thomas v Mowbray, a High Court of Australia case turning on the Constitutional validity of terrorism-related control orders, Callinan J offers a re-evaluation of the Court’s earlier decision in the Australian Communist Party case to curtail executive power. According to Callinan J, factual matters knowable (but not known) at the time of the earlier decision might have given rise to a different outcome. In a dissenting judgment by Kirby J in the same case the Court’s reasoning in the Australian Communist Party case is robustly defended. These contested issues connect with the theoretical dispute between ‘common law constitutionalism’ and ‘constitutional positivism’ analysed by Dyzenhaus in the context of states of emergency where the limits of executive action and the role of supporting facts become particularly salient. They press the question of the status of the rule of law in the international as well as in the municipal sphere.