Standard of Care. Armstrong v. Royal Victoria Hospital
In Armstrong v. Royal Victoria Hospital (Ont CA, 2019) the Court of Appeal held that gauging the standard of care in negligence by the outcome of events was an error which amounted to holding the defendant to an absolute duty:
 For these reasons, it is generally an error of law to use outcomes or goals as the standard of care.. Saumur v. Antoniak
 In Fullowka v. Pinkerton’s of Canada Ltd., 2010 SCC 5 (CanLII),  1 S.C.R. 132, miners were killed by an explosion in a mine shaft during a labour dispute. Someone entered the mine to plant the trip-wired explosives that caused the deaths. Pinkerton’s had been hired to provide security and they were sued in negligence for their role in failing to prevent the bomber from entering the mine shaft. The trial judge found Pinkerton’s to have breached the requisite standard of care because “it had failed to ensure the entrances were properly guarded to avoid incursions”. Cromwell J., who delivered the decision for the court, held that this was an error. First, this measure “required Pinkerton’s to ensure there was no clandestine access to the mine” which is “an absolute duty, not a duty of reasonable care.” Second, the trial judge failed to “indicate what ‘properly’ guarding the entrances required Pinkerton’s to do”: Fullowka, at para. 80.
 Negligence standards of care are to be measured by the behaviour that a relevant prudent person would undertake, rather than the results that prudent person would seek to attain or avoid. Gonthier J. affirmed this general imperative in an instructive Quebec civil law medical malpractice case, St-Jean v. Mercier, 2002 SCC 15 (CanLII),  1 S.C.R. 491, at para. 53:
The correct inquiry to be made in assessing whether a professional committed a fault is indeed to ask whether the defendant behaved as would a reasonably prudent and diligent fellow professional in the same circumstances. To ask, as the principal question in the general inquiry, whether a specific positive act or an instance of omission constitutes a fault is to collapse the inquiry and may confuse the issue. What must be asked is whether that act or omission would be acceptable behaviour for a reasonably prudent and diligent professional in the same circumstances. The erroneous approach runs the risk of focussing on the result rather than the means. Professionals have an obligation of means, not an obligation of result. [Citations omitted; emphasis in original.] The same general point was made in a case analogous to this one, Carlsen v. Southerland, 2006 BCCA 214 (CanLII),  B.C.J. No. 973. In setting aside the liability finding made against a spinal surgeon who “went beyond the annulus fibrosus of the disc and cut the iliac artery and the common iliac vein” when performing a discectomy, Kirkpatrick J.A. held, at para. 15:
[I]n the trial judge’s reasons, he concluded that “the simple precaution that Dr. Southerland should have taken was to ensure that he not let his instruments penetrate past the annulus fibrosus.” In this respect, the trial judge improperly focused only on the result of the surgery, and not on the precise manner in which Dr. Southerland failed to meet the appropriate standard of care. In the result, he held Dr. Southerland to a standard that amounted to a guarantee. That such a standard has never been the law is exemplified in the passage from Greaves & Co. (Contractors) Ltd. v. Baynham Meikle & Partners,  3 All E.R. 99 at 103-104,  W.L.R. 1096 (C.A.), per Lord Denning M.R.:
The law does not usually imply a warranty that [a professional] will achieve the desired result, but only a term that he will use reasonable care and skill. The surgeon does not warrant that he will cure the patient. Nor does the solicitor warrant that he will win the case. [Emphasis added.]
In Saumur v. Antoniak (Ont CA, 2016) the Court of Appeal stated this standard of care for children:
 The parties agree that the test to be applied in determining negligence, including contributory negligence, in the case of children is that articulated by this Court in Nespolon v. Alford, 1998 CarswellOnt 2654 (C.A.), at para 53:. 118143 Ontario Inc. (Canamex Promotions) v. Mississauga (City)
In determining the appropriate standard of care for children, the test is whether a child exercised the care expected from children of like age, intelligence and experience (McErlean v. Sarel (1987), 1987 CanLII 4313 (ON CA), 61 O.R. (2d) 396 (Ont. C.A.), at pp. 411-12 and McEllistrum v. Etches, 1956 CanLII 103 (SCC),  S.C.R. 787 (S.C.C.); Heisler v. Moke (1971), 1971 CanLII 625 (ON SC),  2 O.R. 446 (Ont. H.C.) at p. 448 (per Addy J.), see also Downing v. Grand Trunk Railway (1921), 1921 CanLII 452 (ON SC), 49 O.L.R. 36 (Ont. H.C.) at p. 40). This is both an objective and subjective standard, which acknowledges the need for individualized treatment along with the need for consistency in the law.
In 118143 Ontario Inc. (Canamex Promotions) v. Mississauga (City) (Ont CA, 2016) the Court of Appeal discusses the 'standard of care' element of the tort of negligence:
 To make out a claim in negligence, a plaintiff must establish three things. First, that the defendant owed a duty of care to the plaintiff. Second, that the defendants’ conduct fell below what could be expected of the ordinary, reasonable and prudent person in the circumstances. Third, that the plaintiff suffered damages as a consequence of the defendant’s breach of the standard of care: see Ryan v. Victoria (City), 1999 CanLII 706 (SCC),  1 S.C.R. 201, at paras. 21-28; Hill v. Hamilton-Wentworth (Regional Municipality) Police Services Board, 2007 SCC 41 (CanLII),  3 S.C.R. 129, at para. 93.. Mabe Canada Inc. v. United Floor Ltd.
 I am concerned only with the second of the three requirements. In Ryan, at para. 28, Major J. observed:
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. This court applied the general language in Ryan to a claim of negligent enforcement of a bylaw in Rausch v. Pickering (City), 2013 ONCA 740 (CanLII), 369 D.L.R. (4th) 691, at paras. 87-88:
The approach to determining the standard of care in these circumstances would be assess what a reasonable by-law enforcement officer would have done in considering whether to enforce the By-law against Mr. Rausch. It is at this stage of the analysis that the court must define the conduct required to satisfy this standard, bearing in mind that the FFPPA imposes no obligation on the City to apply to the Board for a determination as to whether a targeted farming operation is a “normal farm practice”.The appellants’ rely on Rausch and argue that the same factors identified by Epstein J.A. are relevant to the determination of the standard of care in this case.
Municipalities are presumed to know the law. Further, this court has held that enforcement officers are obliged to (i) act in good faith in relation to their decisions as to how a by-law will be enforced, and (ii) act with reasonable care in any steps they take to enforce a bylaw. The combination of these two factors – presumed knowledge of the law and an obligation to act reasonably and in good faith in enforcing it – and the wording of s. 444 of the Municipal Act mentioned above, may be relevant to the determination of the standard of care. Specifically, it may permit a finding that when attending at Mr. Rausch’s premises and observing livestock in circumstances that appeared farm-like, the by-law enforcement officer ought to have considered the implications of the FFPPA before proceeding with enforcement steps. [Citations omitted]
 Ordinarily, and absent a statutory provision to the contrary, the plaintiff must plead and prove the essential elements of a negligence claim, including the applicable standard of proof and the defendant’s failure to meet that standard: see Allen M. Linden & Bruce Feldthusen, Canadian Tort Law, 10th ed. (Toronto: LexisNexis Canada, 2015), at pp. 267-68; see also Snell v. Farrell, 1990 CanLII 70 (SCC),  2 S.C.R. 311.
In Mabe Canada Inc. v. United Floor Ltd. (Ont CA, 2017) the Court of Appeal comments on the use of industry practice to inform the standard of care element of negligence:
 Third, although it is clear that conformity with standard practice in an industry does not necessarily insulate a defendant from a finding of negligence, as the Supreme Court explained in ter Neuzen v. Korn, 1995 CanLII 72 (SCC),  3 S.C.R. 674, at p. 698, a practice will be judged negligent “only where the practice does not conform with basic care which is easily understood by the ordinary person who has no particular expertise in the practices of the profession” – only where it is “fraught with danger”.. Fordham v. Dutton-Dunwich (Municipality)
In Fordham v. Dutton-Dunwich (Municipality) (Ont CA, 2014) the Court of Appeal reversed a trial judgment holding a muncipality 50% liable for damages to a driver who ran a stop sign at high speed. The trial judge located negligence on the municipality for not posting a 'sharp turn ahead' warning sign ahead in an area where it was "a local practice in this rural area for drivers to go through stop signs" (!). The appeal court relieved the municipality of any liability, stating:
 More precisely, this appeal turns on the standard of care a municipality must meet in fulfilling its duty of reasonable repair, and the application of that standard to the facts. A municipality’s standard of care has been thoroughly canvassed in two cases: the Supreme Court of Canada’s decision in Housen v. Nikolaisen, 2002 SCC 33 (CanLII),  2 S.C.R. 35, a case perhaps better known for its discussion of the standard of appellate review; and Howden J.’s decision in Deering v. Scugog (Township), 2010 ONSC 5502 (CanLII), 3 M.V.R. (6th) 33, which this court affirmed in a brief endorsement: 2012 ONCA 386 (CanLII), 33 M.V.R. (6th) 1, leave to appeal to S.C.C. refused,  S.C.C.A. No. 351.. 495793 Ontario Ltd. (Central Auto Parts) v. Barclay
 In brief, a municipality has a duty to prevent or remedy conditions on its roads that create an unreasonable risk of harm for ordinary drivers exercising reasonable care. In other words, a municipality’s standard of care is measured by the “ordinary reasonable driver”. Ordinary reasonable drivers are not perfect drivers; they make mistakes. As Howden J. wrote in Deering, at para. 154:
In conclusion, I accept what have become the submissions of all counsel that road authorities have a duty to ordinary motorists to keep their roads in reasonable repair, including the type and location of the road. The standard of care uses as the measure of reasonable conduct the ordinary reasonable driver and the duty to repair arises wherever an unreasonable risk of harm exists on the roadway for which obvious cues on or near the road are not present and no warning is provided, subject to the defences of no knowledge and reasonable steps to prevent and minimum standards compliance. The ordinary motorist includes those of average range of driving ability – not simply the perfect, the prescient, or the especially perceptive driver, or one with exceptionally fast reflexes, but the ordinary driver who is of average intelligence, pays attention, uses caution when conditions warrant, but is human and sometimes makes mistakes. But – and this is the important point for this appeal – a municipality’s duty of reasonable repair does not extend to making its roads safer for negligent drivers. In Deering, Howden J. made this point succinctly, at para. 142: “The standard of care of road authorities rests on the notion of the ordinary motorist driving without negligence”.
 And again, at para. 155:
It is not the law in Canada that the duty of road authorities goes beyond the duty to keep their roads in reasonable repair for the ordinary driver exercising reasonable care, to include drivers who, for instance, do not pay attention, drive at excessive speeds, drive too close to the vehicle in front and who are otherwise negligent. A municipality’s duty of repair includes erecting and maintaining proper signs: see The Queen v. Jennings, 1966 CanLII 11 (SCC),  S.C.R. 532. And, where hazards are hidden or “not readily apparent to users of the road”, a municipality may have a duty to install warning signs. A municipality’s duty to install signs, however, is simply an application of the general standard of care. Signs are required only if without them, an ordinary driver exercising reasonable care would be exposed to an unreasonable risk of harm. Thus, the mere presence of a hazard does not require a municipality to put up a warning sign; the hazard must be one that puts reasonable drivers at risk. See e.g. Greenhalgh v. Douro-Dummer (Township), 2009 CanLII 71014 (ON SC),  O.J. No. 5438 (Sup. Ct. J.), at para. 17; aff’d 2012 ONCA 299 (CanLII).
 I conclude that the trial judge’s finding of a local practice of running stop signs, which Dutton-Dunwich knew about, was an unreasonable finding.
 Second, and more important, the law. Even if the evidence did support the trial judge’s finding of a local practice, this finding cannot be used to impose liability on Dutton-Dunwich for two reasons. First, the local practice the trial judge endorsed nonetheless amounts to negligent driving. As Iacobucci J. said in Waldick v. Malcolm, 1991 CanLII 71 (SCC),  2 S.C.R. 456, at p. 473: “[N]o amount of general community compliance will render negligent conduct ‘reasonable’”.
 Second, the trial judge in effect created two categories of drivers: ill-defined ordinary rural drivers who frequently run stop signs, and all other ordinary drivers who habitually obey stop signs. In the trial judge’s opinion, a municipality’s duty of repair extends to both categories of drivers. This is, as Dutton-Dunwich says in its factum, “an invitation to traffic chaos.” It is also not the law in this country.
 The Highway Traffic Act establishes a uniform set of rules of the road, which applies to all drivers, whether they drive on city roads or rural roads. It could hardly be otherwise. As I said earlier, a municipality’s duty to keep its roads, city or rural, in a reasonable state of repair extends only to making its roads safe for reasonable drivers, not negligent ones. If a road is safe for a reasonable driver – as was the Willey Road–Erin Line intersection – then a municipality has no duty to put up additional signs or take other precautions to prevent accidents that will occur only if a driver is negligent.
 If this is the law on a municipality’s standard of care, the trial judge’s reasons contain an irreconcilable conflict. The trial judge could impose liability for non-repair only by finding that in rural areas driving through stop signs was reasonable driving. Yet, when she came to apportion liability, she found that in running the stop sign, Fordham was negligent. These two findings cannot be reconciled. Running stop signs, even on rural roads, is negligent driving. A municipality has no duty to install warning signs that are unnecessary for reasonable drivers.
In 495793 Ontario Ltd. (Central Auto Parts) v. Barclay (Ont CA, 2016), a negligent investigation case, the Court of Appeal discusses the standard of care applicable to professional negligence, and in particular the need for expert evidence on the content of the standard of care:
 For the reasons that follow, I conclude that the trial judge erred by deciding the content of the standard of care without expert evidence. There are two exceptions to the general rule that expert evidence is required. Neither exception applies here. Without such evidence, there was no basis for determining the appropriate content of the standard of care of a reasonable Thunder Bay police officer conducting a specialized investigation into stolen auto parts, and consequently no basis upon which the trial judge could find that the standard had been breached.
 Moreover, as she proceeded, the trial judge committed the additional errors discussed below. With the exception of the parties’ agreement as to damages for loss of and damage to seized property, the trial judge should have dismissed the respondents’ action.
(1) The Lack of Expert Evidence on Standard of Care
(a) The Standard of Care
 The appropriate standard of care for the tort of negligent investigation was established by the Supreme Court of Canada in Hill v. Hamilton-Wentworth Regional Police Services Board, 2007 SCC 41 (CanLII),  3 S.C.R. 129. The “flexible overarching standard” is that of “a reasonable police officer in similar circumstances”: Hill, at para. 68. As explained by the Chief Justice, at para. 73:
The standard is not perfection, or even the optimum, judged from the vantage of hindsight. It is that of a reasonable officer, judged in the circumstances prevailing at the time the decision was made — circumstances that may include urgency and deficiencies of information. The conduct of a reasonable police officer may vary depending on the stage of the investigation and the legal considerations. In laying charges, the standard is informed by the legal requirement of reasonable and probable grounds to believe the suspect is guilty: Hill, at para. 55.
 The Supreme Court of Canada in R. v. Storrey, 1990 CanLII 125 (SCC),  1 S.C.R. 241, at pp. 250-251, defined the concept of reasonable and probable grounds as requiring an arresting officer to subjectively have reasonable and probable grounds on which to base the arrest. It must also be justifiable from an objective point of view but need not demonstrate anything more. See also: R. v. Feeney, 1997 CanLII 342 (SCC),  2 S.C.R. 13, at para. 24. In other words, “a reasonable person placed in the position of the officer must be able to conclude that there were indeed reasonable and probable grounds” to make an arrest: R. v. Storrey, at p. 251.
 The police are not required to establish a prima facie case for conviction before making an arrest: R. v. Storrey, at p. 251; Wong v. Toronto Police Services Board, 2009 CanLII 66385 (ON SC), 2009 CanLII 66385, 2009 CarswellOnt 7412 (S.C.), at para. 54; Gioris v. Toronto Police Services Board, 2012 ONSC 6396 (CanLII), 2012 CarswellOnt 15071, at paras. 68-70. As explained by Thorburn J. in Wong, at para. 61:
The determination as to whether reasonable grounds exist is based upon an analysis of the circumstances apparent to the officer at the time of the arrest and not based upon what the officer or anyone else learned later. Reasonable grounds still exist where the information relied upon changes at a future date or otherwise turns out to be inaccurate. The requirement is that the information be reliable at the time the decision was made to arrest the accused. The function of police is to investigate incidents which might be criminal, make a conscientious and informed decision as to whether charges should be laid and present the full facts to the prosecutor: Wong, at para. 56. Although this requires, to some extent, the weighing of evidence in the course of investigation, police are not required to evaluate the evidence to a legal standard or make legal judgments. That is the task of prosecutors, defence lawyers and judges: Hill, at para. 50.
 Nor is a police officer required to exhaust all possible routes of investigation or inquiry, interview all potential witnesses prior to arrest, or to obtain the suspect’s version of events or otherwise establish there is no valid defence before being able to form reasonable and probable grounds: Kellman v. Iverson, 2012 ONSC 3244 (CanLII),  O.J. No. 2529, at para. 16; Wong, at para. 59.
(b) The General Rule is that Expert Evidence is required
 The general rule is that the content of the standard of care of a professional, such as a police officer, will require expert evidence: Meady v. Greyhound Canada Transportation Corp., 2015 ONCA 6 (CanLII), 329 O.A.C. 173, at paras. 34-35; Krawchuk v. Scherbak, 2011 ONCA 352 (CanLII), 106 O.R. (3d) 598, at para. 130, leave to appeal to S.C.C. refused,  S.C.C.A. No. 319; Bergen v. Guliker, 2015 BCCA 283 (CanLII), 75 B.C.L.R. (5th) 351, at paras. 114-131; Camaso Estate v. Saanich (District), 2013 BCCA 6 (CanLII), at paras. 71-72, leave to appeal to S.C.C. refused,  S.C.C.A. No. 92.
 As Smith J.A. explained on behalf of the Court of Appeal for British Colombia in Bergen v. Guliker, at para. 131:
While there are cases in which the breach of the standard of care will be apparent without expert evidence, typically when a suit is brought for professional negligence it is customary (and generally necessary), for there to be expert evidence on the standard of care. As the analysis in Hill makes clear, police officers are professionals and their conduct should be assessed in the same way that other professional negligence claims are evaluated. [Citations omitted.] Strathy C.J.O. in Meady explained that that general rule is subject to the exception for “nontechnical matters or those of which an ordinary person may be expected to have knowledge”. See also Krawchuk, at para. 133.
 Whether expert evidence as to the standard of care of a police officer is required turns on the nature of the issues and the facts of each case, with particular regard to the specialized or technical nature of the circumstances, and whether a trier of fact can rely on its own knowledge and experience to determine the appropriate standard of care and whether it is met.
 Epstein J.A., on behalf of this court in Krawchuk, identified two exceptions to the general rule that it is not possible to determine professional negligence without the benefit of expert evidence. The first, as mentioned above, is in nontechnical matters within the knowledge and experience of the ordinary person. The second is where the impugned actions are so egregious that it is obvious that the defendant’s conduct has fallen short of the standard of care without even knowing precisely the parameters of the standard of care. Epstein J.A. explained, at para. 135, that “this second exception involves circumstances where negligence can be determined without first identifying the parameters of the standard of care rather than identifying a standard of care without the assistance of expert evidence.”
 Several appellate cases have considered the application of the general rule and its exceptions.
 In Meady, this court deferred to the trial judge’s decision that he did not require expert evidence to determine the professional standard of care and dismissed the appeal. Meady was an action in negligence against two OPP officers and their employer by a number of passengers and the driver of a Greyhound bus. The bus crashed after a man, with whom the police had contact before boarding, grabbed the steering wheel. The trial judge held that the proposed police expert was not properly qualified and that, in any event, expert police evidence was unnecessary. The issue of appropriate police training, policies, investigation techniques and interaction with the public fell within the understanding of the trier of fact. The only live issue was whether crisis management should have been employed, and the training document to which the proposed expert referred was before the trial judge. The Chief Justice observed, at para. 47, that “[t]he exercise of police powers of investigation, arrest and detention and police interactions with the public falling short of coercion, are part of the daily diet of judges of the Superior Court.” Expert evidence was not required to understand or apply the standards set out in those materials or to assess whether the officers had properly applied their training.
 The Court of Appeal for British Columbia in Bergen allowed an appeal by the province from a judgment finding it 20% liable for a collision following a police pursuit. The court found that the determination of whether the standard of care was breached, following commencement of the police pursuit in question, required expert evidence on how a reasonable police officer would have gone about apprehending a mentally unstable and suicidal individual in the circumstances without causing harm to others. The court held that the proffered expert evidence was properly ruled inadmissible by the trial judge, but as a result, there was no basis for determining the appropriate standard of care and no basis upon which the judge could make key findings of fact related to whether a breach of the standard of care occurred. The court concluded that the trial judge had erred. In the absence of expert evidence, the judge could not have determined the content of the standard of care and could not adjudicate the claim.
 In Camaso Estate, the trial judge had found that expert evidence was required in a police negligence case in which the officer fatally shot the respondent’s husband. The Court of Appeal for British Columbia allowed the appeal because the trial judge did not refer to the expert evidence but rather imposed his own standard of care without any evidentiary basis.
 In Roy v. British Columbia (Attorney General), 2005 BCCA 88 (CanLII), 251 D.L.R. (4th) 233, leave to appeal to S.C.C. refused,  S.C.C.A. 188, the death of an individual from extreme intoxication while in custody was at issue. On appeal, the majority of the court concluded that the trial judge erred by finding that the officers did not perform any adequate assessment or investigation into Mr. Roy’s state of consciousness or consider whether his significantly reduced level of awareness might require medical examination, in the absence of evidence of what a competent police officer would do in the circumstances. The issue related to matters beyond common experience and it was not a matter of a “non-technical nature or of which an ordinary person may be expected to have knowledge” and as such, expert evidence on the standard of care was necessary.
 In those police negligence cases in which the judge has proceeded without expert evidence, the case has been straight forward in nature: see Russell v. York Police Services Board, 2011 ONSC 4619 (CanLII); Lawrence v. Peel Regional Police Force, 2009 CanLII 19934 (ON SC); Wong.