The consequences of a man's OWN action of having coitus sex is the need for an abortion. He is certainly at least 50% responsible for the costs of same, IMO. But any liability beyond that aren't consequences of *HIS* action they're consequences of *HER* (in)action. Legally, one intends the reasonably foreseeable consequences of his own action. If I negligently hit someone with a car, my liability is not absolved should the victim's treating doctor also act negligently such negligence is reasonably foreseeable.
A victim of a tort, however, does have a duty to mitigate damages. Unlike the unconscious victim of an automobile accident, whose only choice is to lay there and get treated by whatever quack might happen along, a woman exercises a free choice over whether the damages are small (cost of an abortion) or whether they are huge (18+ years of child support). Her failure to mitigate the damages cannot be assigned to HIS "tortious" behavior, only the damages which would USUALLY flow from an unexpected conception by unmarried adults the cost of an abortion.