I think that rape is considered a life-threatening situation regardless of HIV status. Think about it, how is a rapist to subdue a victim without threatening the victim's life?
not always, especially if the situation is gang rape, where the assailants can use mere physical force so subdue the victim.
but i agree. it should always be considered life-threatening. its just a matter of whether or not police will agree. however, i can just see some liberal attourney whining "all he wanted was sex, he wasn't going to kill you..."