The thing you have to understand is that in Medieval Europe, a crime such as rape wasn't seen as a crime against a person, but a crime against morality. In some cases, both the raped and the rapist would be condemned, sometimes to execution, for crimes against morality.

"Rape" wasn't really the crime, it was more seen as a sin of flesh. So that's how you would expect rape victims to be treated : like sinners.

The main author I know on the subject is Georges Vigarello, looks like his History of rape is available in english.