All i can say is
she must be tough as she got back up after that !
There's other things you can do like holding arms or wrists even in such an enclosed space, he wasn't reacting to protect himself, he got up considering what to do, did it, then said something about acting like a man and being treated like one..
He could have stopped her in some other way.
Ok had they been evenly matched in size, or sex (not that i think it's a sex issue, i've clobbered male bullies at school and men in clubs who thought they could grope me) i wouldn't be bothered.
The second link, i am fully aware that a gang of girls can be vicious.
On the face of it he did what needed to be done to make them leave him alone, only they wouldn't have, would they.. and they were videoing him.. i bet after that ended they carried on attacking him.. but i bet they stayed at arms length.
The only 2 videos i've seen with violence on youtube that i didn't have any problem with was:
A lad hitting his girlfriend then getting a pasting from a bloke who took offence to it.
A 'happy slapping' video where a guy assaulted another guy walking past who, once over the shock, went and kicked his arse.
For me personally as an adult now, violence is unacceptable unless used in self defence and not over the top response, enough for you to be able to flee an attacker ect.