“In Leitch v. Novac, 2020 ONCA 257, 150 O.R. (3d) 587, at para. 44, leave to appeal refused, [2020] S.C.C.A. No. 194, the Court of Appeal reiterates the significance of non-disclosure in family court as a metastatic cancer of family law:
As the Supreme Court suggested in Leskun v. Leskun, 2006 SCC 25, [2006] 1 S.C.R. 920, at para. 34, nondisclosure is the cancer of family law. This is an apt metaphor. Nondisclosure metastasizes and impacts all participants in the family law process. Lawyers for recipients cannot adequately advise their clients, while lawyers for payors become unwitting participants in a fraud on the court. Judges cannot correctly guide the parties to a fair resolution at family law conferences and cannot make a proper decision at trial. … In sum, nondisclosure is antithetical to the policy animating the family law regime and to the processes that have been carefully designed to achieve those policy goals.
The consequences of failing to disclose or a pattern of inadequate disclosure may vary.
For example, in Blatherwick v. Blatherwick, 2015 ONSC 2606, 8 E.T.R. (4th) 30, Ricchetti J. declined to admit a revised expert report that was introduced at trial. The revised expert report included previously undisclosed financial documentation dealing with the valuation of certain companies. In explaining his decision not to admit the report, Ricchetti J. reiterated the above excerpt from Iannarella to emphasize the importance of full and complete disclosure to civil litigation and trial fairness. He also referred to the Family Law Rules, O. Reg. 114/99, which incorporate by reference the disclosure requirements of the Rules of Civil Procedure, R.R.O., Reg. 194. Rule 19 of the Family Law Rules makes it clear that timely and full disclosure of every document relevant to an issue in the case is the rule. If a party does not produce the document, and it is favourable to the party’s case, that party may not use the document except with leave of the court: at paras. 12-13 of Schedule C (Admissibility Ruling).
In Katz v. Nimelman (2007), 2007 CanLII 51340 (ON SC), 46 R.F.L. (6th) 392 (Ont. S.C.), at para. 65, aff’d 2009 ONCA 445, the court drew an adverse inference against the wife at a trial throughout which “disclosure was a continuing thread.” The court concluded that the wife took unreasonable positions in response to requests for disclosure, and drew an adverse inference due to her failure to disclose. The adverse inference went to her credibility, and any doubt resulting from the inadequacy of her disclosure was resolved in her husband’s favour: at paras. 74, 81.”