I’m gonna be honest, I know we’re dunking on the dude but, that’s a completely valid question? Like I’d also be concerned if a female subordinate was called into their drunken male superiors room late at night. Abuse of authority is a real thing and even though WE know ML is an upstanding dude and that FL came of her own volition, if something WAS shady and I didn’t at least ask I’d feel awful.
I get your point, but there are things that made his question rubs me the wrong way:
1. He asked him, instead of her. If you want to ask out of genuine concern you'd ask the subordinate first. If she appears under duress, then you might have a case.
2. Related to his decision not to ask her first: he has a motive not to. He's interested in her and she already put a wall between them, he doesn't want his questioning further jeopardize his already infinitesimal chance.
These two things get me to think that he asked (and the way he asked) out of his own interest, and deserves to get told.