I didn't see what exactly the context of this situation was, but most comedians don't repeatedly attack a specific person unless they were heckling. If she was part of the presentation or was just there not heckling, yeah, it's over the line and simply being an asshole, not a comedian.
Ah, good point on the apology.
When you say within the context of comedy, that's pretty broad. You think it's appropriate to single someone out, that there's some special immunity that all comedians have? You don't think a comedian can bully or harass simply because he's on stage? That if he says those same things when not on the stage, it's somehow different? It can definitely go over the line when repeatedly targeting a specific person, whether people are laughing or not. It's not as if "humor" has never been used to dehumanize marginalized groups before.
It depends on the circumstance. To me if you show up to a comedy club, that club is the main act's house and you're entering it. Either like what he says or leave.
