Case: Mann v Carnell [1999] HCA 66 ; (1999) 201 CLR 1 
Outcome: applied
Both parties accepted that all of the documents and parts of documents that were ordered to be released, and those sought by way of cross-appeal, were entitled to the benefit of legal professional privilege, being either legal advices themselves or documents extracting or summarising legal advice. The basis of the AAT's decision, seeking to apply the principle discussed by the High Court in Mann v Carnell [1999] HCA 66 ; (1999) 201 CLR 1, was that certain other documents, which were produced pursuant to the Freedom of Information request, disclosed the substance of the advices reflected in the nine documents not produced thereby waiving legal professional privilege in the underlying advices. The issue has been argued before the AAT and in this proceeding on the basis of the application of the common law rather than the Evidence Act 1995 (Cth). That approach is consistent with the decision in Mann [1999] HCA 66 ; 201 CLR 1 and with the approach of the Full Court in Bennett v Chief Executive Officer, Australian Customs Service [2004] FCAFC 237 ; (2004) 140 FCR 101. The AAT identified parts of five particular documents which it held disclosed the substance of the advices in question. One of those documents notes taken as to what occurred at a without prejudice meeting between Australian Taxation Office representatives and taxpayers' representatives including the counsel in question was taken into account on the basis that disclosure of the document waived the without prejudice privilege and so was held to be available to be utilised in relation to waiver by disclosure. 13 Even if there were, there was no use of the material that was disclosed that was inconsistent with maintaining confidentiality in the underlying advices within the principles enunciated in Mann [1999] HCA 66 ; 201 CLR 1. Gleeson CJ, Gaudron, Gummow and Callinan JJ said (201 CLR 1 at [28] [29]): 'Legal professional privilege exists to protect the confidentiality of communications between lawyer and client. It is the client who is entitled to the benefit of such confidentiality, and who may relinquish that entitlement. It is inconsistency between the conduct of the client and maintenance of the confidentiality which effects a waiver of the privilege. ... Waiver may be express or implied. Disputes as to implied waiver usually arise from the need to decide whether particular conduct is inconsistent with the maintenance of the confidentiality which the privilege is intended to protect. ... What brings about the waiver is the inconsistency, which the courts, where necessary informed by considerations of fairness, perceive, between the conduct of the client and maintenance of the confidentiality; not some overriding principle of fairness operating at large.' 14 Those well known general statements are illuminated by the decision in Benecke v National Australia Bank (1993) 35 NSWLR 110 that was used as an example in the joint judgment in Mann [1999] HCA 66 ; 201 CLR 1. In that case the client, on whose behalf a case was settled by counsel, brought proceedings to set aside the settlement claiming that instructions to settle had not been given. She gave evidence to that effect. It was held that, in those circumstances, the client had waived her legal professional privilege and there could be no objection on the ground of privilege to the evidence of counsel or the other legal representatives being given. 16 Similarly, the majority in Mann (201 CLR 1 at [34]) said: 'Disclosure by a client of confidential legal advice received by the client, which may be for the purpose of explaining or justifying the client's actions, or for some other purpose, will waive privilege if such disclosure is inconsistent with the confidentiality which the privilege serves to protect.' 17 In my opinion, the Commissioner is correct in submitting that the AAT fell into error on a question of law in not considering whether such disclosure as took place was conduct inconsistent with maintenance of the confidentiality of the underlying advices. Whilst many of the relevant authorities, including Mann [1999] HCA 66 ; 201 CLR 1 and Bennett [2004] FCAFC 237 ; 140 FCR 101, were referred to by the AAT, the correct question is not to be found in the dispositive parts of its decision. If the question had been asked, in my opinion, it could only properly have been answered in the negative. I cannot see any basis upon which it could be said that the production of the documents relied upon for waiver pursuant to a request under the FOI Act could be said to amount to conduct by the Commissioner inconsistent with maintenance of the confidentiality of the underlying advices. That is reinforced by the evidence, accepted by the AAT, that the failure to mask, even if relevant, was inadvertent. 18 Consideration needs to be given to the decision of Sundberg J in Rio Tinto Ltd 224 ALR 299; (2005) 60 ATR 339. It was held that legal professional privilege had been waived in relation to certain documents by reason of what was described as 'issue waiver' (224 ALR 299 at [21] [47]). Sundberg J went on to discuss (obiter) whether disclosure waiver had occurred by reason of reference to advice in a document that was produced and said that he would have so held. His Honour sought to apply the principles laid down in Mann [1999] HCA 66 ; 201 CLR 1. One of the issues discussed was whether or not the respondent voluntarily produced the documents said to waive privilege in the underlying advices. The document had been produced to the other side twice the first pursuant to an application under the FOI Act where no privilege was claimed; the second was in answer to a notice to produce within the course of the litigation before the Court without a claim of privilege. Sundberg J took the view that the document was produced voluntarily and held that it was not relevant that the respondent did not seek to deploy it for any commercial or forensic purpose. With all respect, that reasoning might be applicable if the underlying advice had been produced but, in my opinion, is not applicable to circumstances such as the present. I am, thus, not inclined to follow Sundberg J's dicta. It was, in any event, a particular factual application of the principle and does not purport to lay down any new law. Furthermore, the inadvertent nature of the present disclosure would distinguish this case from the facts before Sundberg J.