Who has the burden of proving loss resulting from the breach of the fiduciary duty?

Lederman, J. stated at paras. 89-90 of his judgment: Coming then to the second issue of who has the burden of proving the loss resulting from the breach of the fiduciary duty, the principle is not that once a breach of fiduciary duty is established, losses are presumed to flow from the breach and the defence bears the onus of proving which losses did not flow from the breach. The plaintiff must establish the loss arising from the breach and the defendant only bears the onus of trying to prove, if it so chooses, that the loss would have been suffered regardless of the breach. Certainly, the general rule is that the plaintiff must establish that it suffered a loss and adduce evidence to quantify that loss. Moreover, with specific regard to fiduciary duty cases, the structure of analysis always seems to be “what loss flows from this breach.” It is not, “what loss has the defence proven did not flow from the breach”. The onus is only on the defendant if it offers the affirmative defence that the loss would have happened anyway. This conclusion would seem entirely consistent with the above noted statement of La Forest J. [in Hodgkinson v. Simms, supra,] that "where the plaintiff has made out a case of non-disclosure and the loss occasioned thereby is established, the onus is on the defendant to prove that the innocent victim would have suffered the same loss regardless of the breach" (p. 200).