Constitutional Law, explained.

No common law defence to false imprisonment for Commonwealth officers who detained in reliance on subsequently overruled High Court authority

The High Court unanimously refused to recognise a novel common law defence that would have immunised Commonwealth officers and the Commonwealth from liability for false imprisonment where detention was conducted under statutory provisions whose validity had been upheld by a prior High Court decision later overruled. The decision affirms that invalid legislation confers no rights and affords no protection ab initio, that judicial declarations operate retroactively, and that the executive's constitutional responsibility to comply with the law cannot be converted into an immunity from the consequences of exceeding lawful authority.