Sometimes it's 100% if the woman chooses to drug and rape a man or go to a sperm donation bank.
But the responsibility for getting pregnant is irrelevant. We are talking about the responsibility to the child after pregnancy has already occurred. At this stage the man is legally responsible (maybe not if he was raped or donated sperm) and there is nothing he can do about it at that point. The law says he is responsible to the child. The woman can escape responsibility to her child by killing it. The woman has more options to escape responsibility than the man has.
Sorry Tom. In the case (A) of the woman going to the sperm bank 1) the man is off the hook and 2) the woman did nothing immoral and 3) if she went to the sperm bank she would not be likely to looking for an abortion a few weeks later. Your other case is ridiculous. A drug strong enough to knock a man completely out like that would make him impotent and is completely unnecessary given the availability of case (A).
All that aside you seem to be having trouble with simple logic here, the cases where the woman wants to "escape responsibility" are those cases where she did not want it in the first place or the situation was forced on her. The man has the very same set of responsibilities when the pregnancy is due to a coupling. He can also escape them by the means you suggest for the woman. By being a moral little boy, keeping his dick in his pants and waiting until marriage. If he takes the worm out for a spelunking, then that is the point where he has crossed the line and bears responsibility.
The real difference in why the woman should have one further chance to opt out is that Loverboy does not face the same harsh realities the woman does in going forward with the unwanted pregnancy. All he has to do is toss them few measly dollars once in a while.