> But the trick is, whatever you believe will in the long run become a self-fulfilling prophecy. For example, if hypothetical Kim believes it was an accident, she might continue to treat her friends the same and so have a better chance of maintaining/improving the relationship.

I wouldn't agree here. It's just as likely that Kim should interpret this as a signal that the relationship is colder than she may have believed, and should act appropriately. Believing you are close friends with someone who doesn't see you that way will just as often cause the relationship to deteriorate as to improve.