Standard of Review

Standard of Review

Standard of review describes the degree of deference an appellate or reviewing court gives to the decision under challenge. In civil appeals, including medical malpractice appeals, the framework comes from Housen v Nikolaisen, 2002 SCC 33, [2002] 2 SCR 235: questions of law are reviewed for correctness, while findings of fact and inferences of fact, including a trial judge’s findings on standard of care and causation, are reviewed only for palpable and overriding error.

This allocation matters enormously on appeal. Because the central findings in a medical malpractice trial are largely factual and depend on the trial judge’s assessment of competing expert evidence, they attract significant deference and are difficult to overturn. On judicial review of a regulatory or discipline decision, a different framework applies, with reasonableness as the presumptive standard following Canada (Minister of Citizenship and Immigration) v Vavilov, 2019 SCC 65.

Posts tagged Standard of Review analyze how Ontario appellate courts and reviewing courts have applied the governing standards in medical malpractice and discipline matters.

Case header: Bradley v Wang with subtitle 'Direct observation outweighs a physician's evidence of usual practice' on a dark blue banner with 'Case Comment' and professional labels at top corners.

Bradley v Wang: A Misplaced Injection, Usual Practice Evidence, and the Mitigation Burden

The Court of Appeal for Ontario dismisses Dr. Wang’s appeal in Bradley v Wang, upholding findings that a tetanus vaccine was injected in the wrong part of the arm, that the misplacement caused an adhesive capsulitis, and that no mitigation defence was made out. The decision confirms that counterfactual proof can be assembled from evidence excluding the competing explanation, and that a defendant who cannot show suitable alternative work was available loses the mitigation argument regardless of the plaintiff’s own efforts.

August 8, 2026

Ibrahimova v Cavanagh: The Court of Appeal Upholds a Causation Finding Built on Inference

The Court of Appeal for Ontario dismisses Dr. Cavanagh’s causation appeal in Ibrahimova v Cavanagh, upholding findings about what would have happened at a tertiary hospital the patient never reached on the relevant day. The decision confirms that a plaintiff can prove a counterfactual treatment path through a specialist from the receiving discipline, without institutional witnesses, and that a defendant who calls no expert in that specialty is unlikely to recast the resulting findings as speculation.

August 8, 2026

Navy title card reading "Pelrine v Chung: Late expert reports and the interests of justice" from paulcahill.ca.

Pelrine v Chung: Late Expert Reports, Rule 53.08, and the Interests of Justice

Rule 53.08 was tightened in 2022 to stop the routine late service of expert reports. In Pelrine v Chung, the Divisional Court held that the correction can be overdone, and that the interests of justice apply throughout the rule rather than only at its second stage. Two excluded defence reports were let in, thirteen months before a jury trial.

August 1, 2026

Navy title card reading "Brown v Meaney: The limits of clinical judgment, affirmed on appeal" from paulcahill.ca, a Paul Cahill case comment.

Brown v Meaney: Clinical Judgment, Informed Consent, and Commonsense Causation on Appeal

The Court of Appeal dismisses the appeal in Brown v Meaney, upholding findings that two pediatric neurologists breached the standard of care and the duty to obtain informed consent when they abandoned a pyridoxine trial in an infant with a rare epilepsy. The decision affirms that a defensible first impression does not excuse the failure to revisit it, and that causation need not be proven with scientific precision.

June 19, 2026

Bradley v Wang: A Misplaced Injection, Usual Practice Evidence, and the Mitigation Burden

Ibrahimova v Cavanagh: The Court of Appeal Upholds a Causation Finding Built on Inference

Pelrine v Chung: Late Expert Reports, Rule 53.08, and the Interests of Justice

Shaw Estate v Handler: The Court of Appeal Upholds Liability for a Failure to Recall After Critical Imaging

Trozzi v CPSO: The Doré Framework and the Limits of Physician Speech

Hanson-Tasker v Ewart: The Limits of the Snell Adverse Inference

Willick v Willard: An Appeal Dismissed With a Note on Trial Reasons

Hacopian-Armen Estate v Mahmoud: An Appeal on Causation and the “Same Class or Kind” Foreseeability Analysis

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Standard of Review

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Concerned about medical negligence? Talk to Paul directly.

Concerned about medical negligence?
Talk to Paul directly.