If this kind of thing happens in an established long-term relationship, I think we can all agree that, while many people may still find it a dubious thing to do, calling it rape is absurd.

Of course this was not a long-term relationship, or even a relationship at all, just a one night stand. But that one night stand having happened does create a certain grey area - it makes some things natural enough that would've been creepy or downright sexual harassment if he'd done them to someone he had no sexual relationship of any kind with. I think just about every sane person would agree that actually having sex with her while she was asleep goes far beyond the level of increased familiarity which their prior consensual sex made justifiable - but it's hard to draw clear lines in that.