i'd say yes it is, but heres something else to think about. i've thought of the same idea (only i didnt care if it was rape or not...) but then i realized, whats holding the person in place? when you 'freeze time', what part of people get 'frozen'? are their bones frozen in place? their muscles? skin? IMO there are 2 possibilities, they either drop lifeless to the ground, or their bones, muscles, skin, etc is all frozen permanently in place.
if they'd drop lifeless, go ahead and rape em.
if they'd freeze, you couldnt move them at all, (i.e., couldnt undress them, etc...) therefore couldnt rape em. if you could move part of them in this situation, they'd be moving even though time is frozen... but you're the only one that can move...
i might not have explained that very cleary, but nonetheless, its something to think about.