(a) Legal professional privilege is an important common law right (not just a rule of evidence).[35]
(b) That right is only destroyed if the right-holder acts inconsistently with the maintenance of the privilege: that is, the relevant inconsistent act needs to be the act of the right-holder, not some other person.[36]
(c) It follows that the combination of the relevance of the confidential material to an issue in the case, and the forensic unfairness that may follow if the material is not made available to the other party, does not of itself bring about waiver: it is the inconsistent act of the right-holder that does that.[37]
(d) Accordingly, the task for this Court is not to make a choice between one public interest or right over another, or to balance 'fairness and justice' against the right-holder's interest in the maintenance of confidentiality. Instead, the task is deciding whether the important common law right has been lost by the right-holder's act of waiver.[38]
(e) The right can be waived even though the right-holder did not subjectively intend to waive it: that is, the waiver can be imputed objectively from the inconsistent acts of the right-holder.[39]
(f) Inconsistency refers to a contradiction between the confidential nature of the communication, on the one hand, and the act of the privilege holder which necessarily lays open the communication to scrutiny, on the other: so inconsistency is the test for waiver because it exposes the contradictory act which effects the waiver.[40]
(g) Relevant inconsistency is found in the making of an assertion (express or implied) or the bringing of a case either about the contents of a confidential communication or which necessarily lays open the confidential communication to scrutiny.[41]
(h) In either event, it is the contents of the privileged communication which the assertion or the case must be about or which is necessarily laid open to scrutiny - not merely some 'state of mind' to which legal advice might be relevant.[42]
(i) Putting a state of mind in issue, even together with a likelihood that legal advice was obtained that might be relevant to the issue (for example, by showing chronological coincidence[43]), is not necessarily enough. The privileged communication must itself be 'central' to the case.[44]
(j) An assessment of whether an act is in fact contradictory and inconsistent may involve questions of judgment and degree.[45]
(k) Because it does not involve a 'balancing exercise' between competing public interests, the waiver of privilege is not determined by the application of a general test of fairness;
(l) Rather, as Mann v Carnell explains, where necessary, considerations of fairness may inform the Court's perception of the essential ingredient of inconsistency[46] - it follows, considerations of fairness are subordinate to the essential test of inconsistency.