You used the wrong word Dogbert. It's not "blame" it's "responsibility". The woman should own some responsibility for the situation they willingly and knowingly (if stupidly) placed themselves in. The blame rests solely on the POS that committed the rape. But the responsibility for being in a situation that anyone with common sense would have left long ago sometimes is shared by the woman. If a woman drinks with a man to the point of inebriation, makes out with him, and climbs into bed with him, then the woman has stupidly partaken in activities which increase her chances of an assault.
Take the hot-button word "rape" out of it for a second. If you walk down the street in the worst part of town with a big fat stack of cash, and your constantly thumbing through it, you are increasing your chances of being mugged, or a victim of an even more violent crime. Yes, you should not have been robbed, but the behavior you exhibited increased your chances of being robbed. Therefore you own some "responsibility" for your cash-less self now.
Common sense means you don't engage in risky behavior. Such behavior increases the chances of bad things happening to you. And while no one deserves such bad things to happen to them, there are some easy steps that a person can take to not increase the risks.
Sorry, I know this is probably a big old piece of flamebait, but it's just the way I see things.