“Counsel for Mr. Mamo also submits that limiting the application of the deemed undertaking accords with the common law rationalization for the rule as recognized by Morden A.C.J.O. in Goodman v. Rossi (1995), 1995 CanLII 1888 (ON CA), 24 O.R. (3d) 359, [1995] O.J. No. 1906 (C.A.), at para. 36, quoting Prudential Assurance Co. v. Fountain Page Ltd., [1991] 1 W.L.R. 756, [1991] 3 All E.R. 878 (Q.B.), at pp. 764-65 W.L.R.:
The rational basis for the rule is that where one party compels another, either by the enforcement of a rule of court or a specific order of the court, to disclose documents or information whether that other wishes to or not, the party obtaining the disclosure is given this power because the invasion of the other party’s rights has to give way to the need to do justice between those parties in the pending litigation between them; it follows from this that the results of such compulsion should likewise be limited to the purpose for which the order was made, namely, the purposes of that litigation then before the court between those parties and not for any other litigation or matter or any collateral purpose[.]”