Even if Emily were rudely heckling every single comedian who went up before her (and it doesn't seem like she was), one person heckling one other person seems a benign act compared to a room full of mostly men attacking a woman who was clearly so nervous to do comedy that she had to get drunk first. (Note to those who want to try comedy: never drink first.) The behavior of the comedians in the audience is at best childish (big surprise!) and at worst barbaric. This should be viewed as the hazing incident it is, meant to intimidate and harass a newbie female who dared disturb the balance of power. Some have argued that a male comedian who behaved in the same way would have been met with the same response, but that's doubtful. Female hecklers are notoriously reviled by male comedians, which is not to say that other female comedians there weren't bothered by her behavior, but rather to draw attention to the latent sexism behind the act of embarrassing this girl online. Putting her in her place, as it were. This is the first video of its kind as far as I know (of an open mic-er being attacked by an audience of fellow comedians) and it's no coincidence that the subject is female.
I often wonder how many female comics with potential wind up steering away from standup because they don't want to navigate the open mic scene. Yes, it's tough for everyone. But it's gotta be even tougher if you're a woman who has to travel to dark basements (or rooms in the back of a bar) that have a 12:1 ratio of guys:girls telling a stream of unfunny jokes that frequently touch on rape or some other aggressive topic. If it makes a numb-to-the-world geezer like me feel uncomfortable, I can only imagine how it might make a young female comic feel.