McGill Faculty of Law: Extra-Contractual Obligations/Torts: Prof. Lara Khoury, 2002-03/Summary by Derek McKee
The judges used the “bon père de famille” test for determining fault. Although no adults were present at the time of the accident, a reasonable adult would not have stopped the girls from sliding on such a small slope. Therefore, the defendant organization was not at fault, and could not be held liable. This case is an illustration of the basic principles of fault.
Courts apply an “objective” fault test in order to:
1. ensure stability and predictability
2. avoid personal bias
3. set a minimum standard for behaviour
Is the reasonable person standard flexible enough to account for social change? Yes, because it is not explicitly defined anywhere.
An example could be changing attitudes about when it’s “reasonable” to wear a condom.
Common law also employs several alterative techniques for determining fault: where it seems that foreseeability and prevention are insufficient criteria:
balancing severity of the harm, probability of harm, and burden of prevention (qualitative approach):
Asks: would a reasonable person have nevertheless taken the risk? (The implication is that there are some risks that are reasonable for one to take.) One must assess:
the probability of damage occurring: one must guard against probable damage, but not against remote possibilities of damage.
the gravity of the potential damage: As the gravity of the potential damage increases, the threshhold of reasonable risk decreases. (e.g. the case of the one-eyed mechanic who lost his second eye)
the burden of precautions: Would precautions have been too heavy?
The social utility of the activity is also sometimes considered, but this is mainly restricted to essential services provided by the government (e.g. police, firefighters).
Bolton v. Stone,  A.C. 850 (H.L.). (CB1p202)
While standing on the street outside her house, Stone was hit and injured by a cricket ball. A visiting player at the cricket club had hit the exceptional shot. According to neighbours and long-time club members, balls very rarely went over the wall. Stone sued for negligence and nuisance.
Could the cricket club be at fault, even though the possibility of the cricket ball hitting someone was extremely remote?
No; the appeal was allowed.
The risk posed by the cricket ball was extremely remote, a “bare possibility,” so a reasonable person would have been justified in failing to take precautions. Lord Reid argued that the burden of precautions was irrelevant unless the gravity or probability of damage was high—in which case cricket should not be played at all. In other words, a small risk can be ignored. (Lord Reid qualified this in Wagon Mound 2.)
This case may be seen as a descendant of Donoghue v. Stevenson. The issue of probability qualifies Lord Atkin’s “neighbour principle.” It is also interesting to note the “social utility” argument used by counsel for the appellants on p. 853. This summary deals only with the tort of negligence, not nuisance.
Overseas Tankship v. Miller Steamship (Wagon Mound 2),  1 A.C. 617 (P.C.). (CB1p212)
The crew of a ship, the Wagon Mound, carelessly spilled a large volume of furnace oil into Sydney Harbour. The oil surrounded two ships belonging to the respondents, which were undergoing repairs including welding. When the manager of the repairs saw the oil, he stopped the work, but resumed it when he was told that furnace oil