“Res judicata, or cause of action estoppel, was recently described by the Court of Appeal in Dosen v. Meloche Monnex Financial Services Inc. (Security National Insurance Company), 2021 ONCA 141. The four criteria were listed by the Court as follows:
[13] The motion judge applied the test for cause of action estoppel set out recently by this court in The Catalyst Capital Group Inc. v. VimpelCom Ltd., 2019 ONCA 354, 145 O.R. (3d) 759, leave to appeal refused, [2019] S.C.C.A. No. 284. She stated:
There is a specific test that has to be met to establish this type of estoppel and it has four requirements to it as follows:
There is a final decision of a court of competent jurisdiction in a prior action. This is conceded by the responding parties and is not at issue here;
The second requirement is the parties to the subsequent litigation were parties to, or in privy with the parties to the prior action;
The third requirement, the cause of action in the prior action is not separate and distinct and;
Fourthly, the basis of the cause of the action and the subsequent action was argued or could have been argued in the prior action, if the parties had exercised reasonable diligence. [Emphasis in original.]
All four of these criteria must be satisfied for res judicata to apply.”