I also disagree. It's not normal to want to have intercourse with children, but not everyone who does that is acting out of an uncontrollable psychological urge and therefore incapable of making choices. I agree that this is about manipulation - if he was a chronic self-harmer, he'd have been doing it throughout the relationship, not just when things didn't go his way. The obvious benefit of feigning unconsciousness is he gets to mess up the ex's life a bit more by making the police consider bringing her in for questioning - since it's likely that in his worldview she IS to blame for the injury by "making" him do it, that's totally in line with the desire to manipulate and control the other person. Domestic abusers often believe that the other person makes them get violent, this is no different.