One Shot, One Opportunity: Cause Of Action Estoppel In Patrick Street Holdings Ltd v. 11368 NL Inc.

The Supreme Court of Canada recently took the opportunity to conduct an in-depth analysis of cause of action estoppel, one of the two branches of the doctrine of res judicata. The decision in Patrick Street Holdings Ltd. v. 11368 NL Inc. 2026 SCC 15 is a helpful restatement of the res judicata framework, specifically cause of action estoppel, and confirms that the doctrine will continue to serve as a crucial procedural protection preventing parties from endlessly relitigating issues that have already been decided.

Background

The dispute between Patrick Street and 11368 stems from a real estate development which was owned by 11368. Patrick Street, among other parties, held mortgages on the development.

Initial Decision – 2017 Decision and 2019 Appeal

In 2016, 11368 defaulted on a mortgage held by Patrick Street. Patrick Street exercised its power of sale and 11368 responded by providing a collateral mortgage of $4 million. Subsequently, Patrick Street restarted its power of sale proceedings and purchased the development. Patrick Street created an accounting report detailing intended payments on various mortgages, including the $4 million collateral mortgage posted by 11368.

In the same year, two mortgage holders challenged the priority of mortgage payments set out in the accounting report, arguing that the $4 million collateral mortgage should be excluded from the report. The Supreme Court of Newfoundland and Labrador agreed and removed the $4 million collateral from the accounting report. On appeal, Court of Appeal upheld the decision.

Subsequent Decision – 2020 Decision and 2024 Appeal

Following Patrick Street’s unsuccessful appeal, 11368 applied for payment of the residual sale proceeds. Patrick Street raised new arguments to refute 11368’s application, including a new claim in contract. 11368 relied on the 2017 decision in support of its position but did not mention res judicata or cause of action estoppel by name. At trial, the Supreme Court ordered the funds to be paid to 11368. Patrick Street’s appeal was dismissed on the basis of res judicata.

Majority Decision – The Test for Cause of Action Estoppel

In his reasons, Chief Justice Wagner grappled with two considerations: the application of res judicata and the process of pleading the doctrine.

Chief Justice Wagner helpfully re-articulated the test for cause of action estoppel which requires: (1) a final decision from a court of competent jurisdiction, (2) the same parties in both the preceding and current actions, (3) the cause of action to not be distinct and separate, and (4) arguments raised in the current proceeding that could have or should have been argued had the parties exercised reasonable diligence. The Court’s review of cause of action estoppel jurisprudence centered on steps three and four. To determine whether a cause of action is distinct, a court will compare of the facts and subject matter of the initial and subsequent proceeding. Similarly, assessing a party’s due diligence in raising legal theories involves looking at the material facts in both proceedings.

Chief Justice Wagner restated the residual discretion a court holds to deny the application of cause of action estoppel even if the factors are otherwise satisfied. Such an exceptional invocation only arises if applying the doctrine would result in procedural unfairness or an injustice for the other party.

The majority also confirmed a ‘functional’ approach to res judicata. To plead cause of action estoppel, a party must include the material facts relied on to demonstrate that both causes of action are the same and raise it at the earliest opportunity or at first instance where possible. The party does not need to mention the doctrine by name. The inquiry focuses on whether the party pleaded the material facts that give rise to cause of action estoppel. This ensures opposing parties are not surprised by the use of the doctrine.

The majority held that cause of action estoppel applied, barring Patrick Street from re-opening its claim to the residual mortgage funds. 11368 sufficiently raised cause of action estoppel as it relied on the 2017 decision and argued that the issue before the court had been previously decided. The majority found that both the 2017 and 2020 decisions were premised on determining the validity, value, and priority of the mortgages. Moreover, Patrick Street could have reasonably brought forth the contract argument in 2017, thus, Patrick Street failed to exercise reasonable diligence to explore all arguments supporting its claim in at that time. The Supreme Court of Canada declined to use its discretion to deny applying cause of action estoppel.

Dissenting Opinions

Justice Martin (joined by Justice Karakatsanis) would have allowed the appeal as in her perspective, 11368 did not raise res judicata at first instance in the 2020 decision. In the eyes of Justice Martin, Patrick Street could not have foreseen that the 2017 decision would disqualify its subsequent claim to the remaining funds. Furthermore, she concluded that an appellate court should have additional discretion to allow a party to raise res judicata for the first time.

Similarly, Justice Côté would have permitted Patrick Street to re-litigate the dispute. Unlike Justice Martin, Justice Côté believed that the 2017 and 2020 decisions were separate and distinct causes of action as they each dealt with the validity, value, and priority of different mortgage holders. Accordingly, the Court should exercise its residual discretion avoid an injustice.

Key Takeaways

This decision is a helpful restatement of the framework for cause of action estoppel. Importantly, any litigant seeking to rely on this doctrine should do so at the earliest possible opportunity. They should also be aware of the discretion a court holds to decline to apply the estoppel. Even so, the bar to raise res judicata has effectively been lowered, as the party raising cause of action estoppel can do so without referring to the doctrine by name.

The content of this article is intended to provide a general guide to the subject matter. Specialist advice should be sought about your specific circumstances.