What is the effect of a conditional termination of an agreement?

On the evidence adduced, I am satisfied that the intention was not other than what was stated in the agreement. Therefore, the result herein should be the same as in Hall v. Hall and Todd v. Todd such that the finality of the agreement should be maintained.

As stated, the parties were functioning under a common mistake, but it was a mistake of law and such cannot vitiate the agreement. On this point I again return to Hall v. Hall where Gerwing, J.A., stated, commencing at the bottom of p. 25 R.F.L.: “The learned trial judge, thus, having found both parties mistakenly believed the shares would not be subject to any claim by the wife, characterized this a common mistake, and further as a common mistake of law and not of fact. This latter conclusion is critical; at common law a mistake of law does not vitiate a contract. The parties were thus held by the learned trial judge to be bound by the contract and the appellant was precluded from seeking a distribution of property now in the name of the respondent. The appellant contends that this mistake is not in fact one of law but rather one of fact, which could in some circumstances vitiate the contract. . . . . . “... Where in fact, a law exists, but the parties are not aware of its extent or its application to them, there is a mistake of law. Lack of awareness of the application or extent of an existing law is another way of stating that the law has been misinterpreted. ... “Thus we are of the view that the characterization of the mistake by the learned trial judge as one of law as opposed to fact was correct. In the result the appeal is dismissed.”