Torts - Negligence - Standard of Care II. Walters v Ontario
In Walters v Ontario (Ont CA, 2017), an interesting jail liability case, the province was sued for injuries resulting when members of two opposing gangs were placed in the same unit, the court commented usefully on the appellate standards of review applicable to the separate elements of negligence:
 At the outset I can advise that I would dismiss Ontario’s appeal. The issues on appeal are three basic elements of a negligence action: duty of care; breach of the standard of care; and causation of damage. The first issue, the determination of a duty of care, is a question of law. Appellate courts review such determinations for their correctness: Ryan v. Victoria (City), 1999 CanLII 706 (SCC),  1 S.C.R. 201, at para. 21; Housen v. Nikolaisen, 2002 SCC 33 (CanLII),  2 S.C.R. 235, at para. 8. The second issue, application of the relevant standard of care, and the third issue, causation of damage, are questions of mixed law and fact. On those matters, this court must not interfere with the trial judge’s findings absent any “palpable and overriding error” or error concerning an “extricable question of law”: Housen, at paras. 29-37, 70, 159.. Owen v. Bains
In Owen v. Bains (Div Ct, 2021) the Divisional Court considered the standard of care in a dental malpractice case:
 In general terms, the standard of care required of a health care practitioner is to exercise a reasonable degree of skill and knowledge and the degree of care that could reasonably be expected of a normal, prudent practitioner of the same experience and standing. The standard of reasonableness is not a standard of excellence that amounts to perfection. To adopt such an approach would amount to a guarantee: Armstrong v. Royal Victoria Hospital, 2019 ONCA 963, 452 D.L.R. (4th) 555, at para 86, van Rensburg J.A., in dissenting, aff’d Armstrong v. Ward, 2021 SCC 1, 452 D.L.R. (4th) 553.
 Where standard of care is at issue, the court must determine what is reasonably required to be done (or avoided) by the defendant in order to meet the standard of care. In a dental malpractice case, the court must determine what a reasonable dentist would have done (or not done) in order to meet the standard of care. The degree of foreseeable risk affects the determination of the standard of care: Armstrong at para 87; McArdle Estate v. Cox, 2003 ABCA 106, 327 A.R. 129.