Apportioning Liability: Third Party Claims vs. Notices To Co-Defendants

When a defendant is sued, there is often another person who may be partially or wholly responsible for the loss of the plaintiff. A plaintiff may choose to sue one party even though more than one party is potentially liable. This is made possible by the common law which places responsibility for the entire loss on each person individually, and is even more likely to happen if one defendant is both wealthy and clearly liable.

The legislation in Alberta has provided some relief to defendants permitting both third party claims and claims against co-defendants. Despite having similar goals, these two statutory mechanisms are fundamentally different in both substance and application.

Third Party Claims

The Alberta Rules of Court broadened the scope of third party claims under rule 3.44. The former rule was limited to claims of indemnity or contribution. This option is still available to a defendant under rule 3.44(a) which allows a defendant to file a third party claim where the third party is or could be liable to the defendant for all or part of the plaintiff's claim. For example, a driver said to have negligently caused an injury to a plaintiff may pursue a third party claim against a doctor if they believe the doctor exacerbated the initial injury through negligent treatment. This increases efficiency because it reduces multiplicity of proceedings.

The changes under 3.44(b) permit a defendant to file an independent claim against a third party, so long as the claim relates to transactions or occurrences involved in the action between the plaintiff and the defendant. An independent third party claim arises when the third party breaches a duty owed to the defendant, which causes the defendant to suffer losses that are factually related to the losses suffered by the plaintiff.

Finally, rule 3.44(c) enables a defendant to file a third party claim where the third party should be bound by a decision between the plaintiff and the defendant. While this has not yet been extensively explored in the jurisprudence, the court noted in O'Connor Associates Environmental Inc. v. MEC OP LLC, 2014 ABCA 140 (O'Connor) that 3.44(c) is "flexible" and that, at this early stage, it should not be "undermined by rigid rules about when it can or cannot be used."

Recently, in O'Connor, the Alberta Court of Appeal identified a baseline requirement for the application of rule 3.44. It was determined that "at a minimum, the third party notice must disclose a legally...