Actually, my doctor told me that the morning after pill will not harm a pregnancy that already exists. All it does is stop you from ovulating or keep you from ovulating so that if you haven't already conceived, you wont.
And yes, I agree that unprotected sex is unprotected sex and she could have gotten pregnant from precum at any time during the intercourse. But, I also understand that when you are trusting your partner not to finish inside of you, then I would be royally pissed if he did too! Even though with no other source of birth control, it may not even matter.
I am on the pill, but also use condoms as much as possible. If I do have sex without a condom I do not let him "finish" in me either. It is just unnecessary risk, but ideally I shouldn't be having sex without condoms anyway.