1Where a party pleads and discloses counsel's advice as a justification for a decision (here, to prosecute), privilege over the underlying brief to counsel — including instructions, observations, and documents provided to counsel — is impliedly waived, because retaining privilege over the brief while disclosing the advice is inconsistent with the maintenance of the confidentiality the privilege protects.
2The governing test for implied waiver of legal professional privilege is the inconsistency principle from Mann v Carnell (1999) 201 CLR 1 and [name withheld] v Secretary, Department of Justice (2008) 234 CLR 275: whether the privilege holder's conduct is inconsistent with maintaining confidentiality, informed by but not governed by considerations of fairness. The broader 'fairness at large' test and the narrower 'confusion or deception' formulation from [name withheld] v State of Queensland are not the applicable standard.
3An application under UCPR r 223(4)(b) for disclosure of documents whose existence and direct relevance are merely speculative will be dismissed; the applicant must establish more than an assumption that documents may exist.
