I think it can go all three ways. Continuing with the rape example:
Victim's Fault:
She goes to a club wearing next to nothing. She lets herself be picked up by a guy who's obviously horny. After some conversation and dancing, he suggests going back to his place...and leaves no guesses as to what they'll be doing there. When they get there, the foreplay begins and she's enjoying every second of it. Then, when they're only seconds away from the actual 'act,' she backs out. Guy goes ahead anyway. She doesn't really put up a fight. In this case, she basically said she wanted sex about 1000 times, and only said no once, and then at a point in time when the guy was too overrun with hormones to really comprehend. Yeah, the guy should have stopped, but who can honestly say with absolute certainty that they have the willpower to do so in said situation. If she didn't want sex, she should have said so instead of screaming 'screw my brains out' with every action she took.
Partial Victim's Fault:
Same scenario, except she says no during the initial necking. The guy clearly could have stopped, but she set herself up in a very comprimising situation by being at a guy's house alone when he made it perfectly clear that the two of them were there to have sex. With the kind of signals he was sending out, it should be pretty clear to anybody with half a brain that she shouldn't have gone to his house.
Not at all the Victim's Fault:
Scenario starts the same, except the skimpy clothing is irrelevant. She goes to a club, talks to a guy. He seems interested in a little nocturnal activity, but she's not. However, she does get a bit tipsy and asks him for a ride home. He does so, follows her in the house, and rapes her. While there were a couple of mistakes she made (such as getting a ride home alone with a stranger), the rape was in no way, shape, or form her fault. That guy is 100% predator.
Anyway, that's my take. Some might draw the lines in different places, but I think these three extreme examples illustrate about where I stand.