On July 15th, the Court of Appeal for Ontario said the following about when an inadvertent disclosure of a solicitor-client communication will result in the waiver of privilege:
Inadvertent disclosure does not necessarily mean that privilege has been waived. While waiver of solicitor-client privilege can be express or implied, whether privilege has been waived by inadvertent disclosure is a fact-specific inquiry, which may include consideration of the following factors:
- The way in which the documents came to be released;
- Whether there was a prompt attempt to retrieve the documents after the disclosure was discovered;
- The timing of the discovery of the disclosure;
- The timing of the application;
- The number and nature of the third parties who have become aware of the documents;
- Whether maintenance of the privilege will create an actual or perceived unfairness to the opposing party; and
- The impact on the fairness, both actual or perceived, of the processes of the court.
See Airst v. Airst (1998), 1998 CanLII 14647 (ON SC), 37 O.R. (3d) 654 (C.J. (Gen. Div.)), at pp. 659-60; and Chapelstone Developments Inc. v. Canada, 2005 NBCA 96 (CanLII), 191 C.C.C. (3d) 152, at para. 55, leave to appeal to SCC refused,  S.C.C.A. No. 38.
In the circumstances, the Court held that a party had not inadvertently waived privilege. The disclosure, however, was not without a consequence. The Court said, “This is not a case for costs, given that the issue arose as a result of the moving party’s own counsel’s error.”