Negligence (General)

Richard v. 2464597 Ontario Inc., 2019 ONSC 2104 (CanLII)

[30] The standard of care in negligence cases is that of a prudent and reasonable person in the circumstances. As stated in Ryan v. Victoria (City), 1999 CanLII 706 (SCC), [1999] 1 S.C.R. 201, at para. 28:

"Conduct is negligent if it creates an objectively unreasonable risk of harm. To avoid liability, a person must exercise the standard of care that would be expected of an ordinary, reasonable and prudent person in the same circumstances. The measure of what is reasonable depends on the facts of each case, including the likelihood of a known or foreseeable harm, the gravity of that harm, and the burden or cost which would be incurred to prevent the injury. In addition, one may look to external indicators of reasonable conduct, such as custom, industry practice, and statutory or regulatory standards. [Emphasis added]"

[36] It is not disputed that in cases alleging professional negligence, expert testimony is generally required. There are two exceptions to this general rule. The first is where the court is faced with non-technical matters or those of which an ordinary person may be expected to have knowledge. The second is where the actions are so egregious that it is obvious that the conduct has fallen short of the standard of care, even without knowing precisely the parameters of that standard: see 495793 Ontario Ltd. (Central Auto Parts) v. Barclay, 2016 ONCA 656 (CanLII), at paras. 53-57.