This is true, and everyone should realize that. Some people have no real theory of mind, and seem to think that people are preprogrammed robots who don't have their own thoughts. It's sad. :/
Hm... then you never know what will happen between them in that case. Like I said, just wait it out. I really do hope that you'll be able to work it out with them. It's hard to say if she's doing it intentionally, or she's just oblivious to the fact that she's done something that could have potentially hurt you. But you'll eventually see both of their true colors while they're together and how it affects your friendship. Good luck.
Haha... Yeah, I try to give them the benefit of the doubt, too. Obviously he cares for you, because he tried to make some legitimate excuse as to his rejecting you, but underestimated how smart you are and that you'd look right through it. I'm sure with time you'll all be at an understanding. You can't get mad at him for not feeling that way about you; it is what it is. But it was your girl friend that should have been the one to consider your feelings first. She must have liked him, too, but didn't want to tell you that. Eventually you'll just have to learn to be happy and supportive of them. Then someone else will come along and you'll forget about this whole thing. That's what tends to happen!