Simple enough principle, maybe best stated in the context of a less traumatic crime - if you leave your keys in the door of a car, you carry some responsibility for it getting stolen. But that in no way should be seen as reducing the guilt of the person who steals the car.

Guilt shouldn't be seen as shared between a victim and a perpetrator of a crime, so that the guilt of the perpetrator is reduced if the victim caries some blame. Plenty of crimes whetre a victim can reasonably be seen as carrying some blame, but that shouldn't be seen as in any way reducing the blame on the perpetrator.