It’s unclear, but I hope he waited until you were stable. If you weren’t stable, then he should have stayed in case the situation became more dramatic than intense pain. Basically, if there is something he needed to be there for.

If he’s just cranky then maybe emotional support is a good reason, although its usually not helpful to have a cranky and irritated person around for emotional support anyway.

If he’s actually non functional without sleep, like he just can’t process information without getting enough sleep, then in most cases you should want him to get to sleep if he’s not needed. This is something you guys should talk about when you’re well rested and not anxious about the ER or sleep deprived.