What is the burden of proving that a doctor failed to meet the standard of care?

The plaintiff has the burden of proving that the defendant doctor failed to meet the required standard of care. In addition thereto, the plaintiff must establish, on a balance of probability that the defendant’s breach caused or contributed to the plaintiff’s injury. However, causation need not be established with scientific precision. It is a question of fact and common sense for the trier of fact to determine whether the evidence establishes that the breach more likely than not caused or contributed to the plaintiff’s injury: Snell v. Farrell, 1990 CanLII 70 (SCC), [1990] 2 S.C.R. 311.