15 In Telstra Corporation Ltd v BT Australasia Pty Ltd (1998) 85 FCR 152 the majority of the Full Court of the Federal Court (Branson and Lehane JJ, Beaumont J dissenting) said that where a party relies on a course of action an element of which is the party's state of mind, including the quality of the party's assent to the transaction, the party is taken to have waived privilege in respect of legal advice which the party had, before or at the time of the relevant events, material to the formation of that state of mind. The majority said at 166-167:
The quality of any particular legal advice, and the extent, if any, to which it was causative of loss and damage, can only properly be assessed once it is placed in the context of the totality of legal advice received by the client. The client, by bringing the proceeding, is taken to have consented to the use of the privileged material, or to have waived reliance on the privilege which would otherwise attach to such material. Reliance on the privileged nature of the material would, in the circumstances, be unjust and would inhibit the proper functioning of the legal process.
Where, as in this case, a party pleads that he or she undertook certain action "in reliance on" a particular representation made by another, he or she opens up as an element of his or her cause of action, the issue of his or her state of mind at the time that he or she undertook such action. The court will be required to determine what was the factor, or what were factors, which influenced the mind of the party so as to induce him or her to act in that way. That is, the party puts in issue in the proceeding a matter which can not fairly be assessed without examination of relevant legal advice, if any, received by that party. In such circumstances, the party, by putting in contest the issue of his or her reliance, is to be taken as having consented to the use of relevant privileged material, or to put it another way, to have waived reliance on the privilege which such material would otherwise attract.
16 Within the overarching principles determined by the High Court on this question of imputed waiver and following, in particular, the approach adopted by the majority in Telstra, I have taken the view that where the applicants, or any one of them, have pleaded, or it was their evidence that, in embarking on a course of conduct, they relied on certain representations or assurances made to them by the respondents (or either one of them), and which are critical to the outcome of the case, the applicants have put into issue their state of mind in embarking on that course of conduct. Where a party has put their state of mind into issue the majority in Telstra said: "The court will be required to determine what was the factor, or what were factors, which influenced the mind of the party so as to induce him or her to act in that way." That cannot be fairly assessed without examination of relevant legal advice.