" …foreseeability of the risk of injury and the likelihood of that risk occurring are two different
things…A risk of injury which is quite unlikely to occur, such as that which happened in Bolton v
Stone, may nevertheless be plainly foreseeable. Consequently, when we speak of a risk of injury
as being "foreseeable" we are not making any statement as to the probability or improbability of its
occurrence, save that we are implicitly asserting that the risk is not one that is far-fetched or
fanciful. Although it is true to say that in many cases the greater the degree of probability of the
occurrence of the risk the more readily it will be perceived to be a risk, it certainly does not follow
that a risk which is unlikely to occur is not foreseeable.
In deciding whether there has been a breach of duty of care the tribunal of fact must first ask itself
whether a reasonable man in the defendant's position would have foreseen that his conduct involved a
risk of injury to the plaintiff or to a class of persons including the plaintiff. If the answer be in the
affirmative, it is then for the tribunal of fact to determine what a reasonable man would do by way of
response to the risk. The perception of the reasonable man's response calls for a consideration of
the magnitude of the risk and the degree of probability of its occurrence, along with the expense, difficulty and inconvenience of taking alleviating action and any other conflicting responsibilities
which the defendant may have. It is only when these matters are balanced out that the tribunal of fact
can confidently assert what is the standard of response to be ascribed to the reasonable man placed in the defendant's position.
The considerations to which I have referred indicate that a risk of injury which is more remote in
the sense that it is extremely unlikely to occur may nevertheless constitute a foreseeable risk. A
risk which is not far-fetched or fanciful is real and therefore foreseeable. But, as we have seen,
the existence of a foreseeable risk of injury does not in itself dispose of the question of breach
of duty. The magnitude of the risk and its degree of probability remain to be considered
with other relevant factors."