What is the burden of proof relating to a hypothetical event in a damages assessment?

While the burden of proof relating to actual past events is a balance of probabilities, a past hypothetical event will be considered in a damages assessment as long as it was a real and substantial possibility and not mere speculation: Athey at para. 27. Rowles J.A. in Smith v. Knudsen, 2004 BCCA 613, rejected the proposition that a claim for past loss of opportunity had to be established on a balance of probabilities. She clarified that the same test applies regardless of whether the court is considering hypothetical events in the assessment of past or future loss of earning capacity. She expounded at para. 29: