I'm not saying Buffy is at fault--I'm not a person who would ever blame the victim, and that scene in the show was adequately horrifying and realistic. She could have definitely done some things differently to help prevent this situation though. She put herself in a bad situation, and confused the hell out of someone who was already confused. Not her fault, but not entirely his either.
My main issue is with the Angel-adoring fans who hate Spike.