Boys Are Stupid...
I am just saying, if you were a boy and you hypothetically went out on a first date with a girl. And it was pretty clear to both of you that probably this isn't going to work out. The correct thing to do, still, is to call her and have that awkward conversation where you both agree you don't really care if you never see each other again. It is not OK to friend that girl on Facebook and not call and give no indication of the fact that, well, you don't really care if you never see her again. It doesn't matter if you are as sure as she is that this is the case. The phone call is necessary. I'm just saying.
End rant.