One other problem I have with blaming the victim is that it tends to encourage a zero-risk (or minimal-risk) ideal towards life.
The "proof" that one has acted imprudently is that something bad has happened. This suggests that if only one had led a more sheltered life, one would have done the right thing. But there is no limit to how sheltered one can make one's life.
For instance, should one avoid all parties that serve alcohol on the off chance that one might get raped? It isn't clear that the less risk one encounters in life, the better a person one is. Risks are a part of life. Perhaps some risks are foolish and should be avoided, but if one's only standard of failure is when something bad happens, that appears to make all risk look foolish.
eudaimonia,
Mark