D carelessly let oil spill into the water, which spread to where X was repairing P’s ship. It was thought unlikely that the oil would catch fire and so X carried on its work. As a result of the continuation of the work, some molten metal set alight the oil, which destroyed P’s ship. P sued D for negligently causing P’s ship to catch fire. HL allowed the claim. HL said that the fire was reasonably foreseeable and therefore D was negligent in spilling the oil and destroying P’s ship. (Tony Weir points out that if the oil setting alight was foreseeable, then X, repairing the boat despite the possibility of the oil setting alight, should surely also be held to have been negligent in causing the destruction of the ship).
Lord Reid: just because a risk is small doesn’t mean that it should not be eliminated: whether the risk is so small as to be not worth changing one’s conduct depends on its size, the cost of removing the risk etc. Bolton v Stone was a case of a risk that was so minimal that inaction was justified. It does not follow that all small risks should be ignored. The risk CAN be ignored where “a reasonable man, careful of the safety of his neighbour, would think it right to neglect it.” This was not the case here. Bolton v Stone didn’t change the general principle that “a person must be regarded as negligent if he does not take steps to eliminate a risk which he knows or ought to know is a real risk and not a mere possibility which would never influence the mind of a reasonable man”