Here again, I agree the girl who got her ass beat started the fight. And if you'll notice, the fight started very quickly. There wouldn't have been time to stop it before it started, at least by what can be seen on the vid. As in most catfights you see posted, one girl usually starts or at least instigates the fight. So if you stop it before it starts, how do you know what will happen?
As long as both girls want to fight, and both want to continue fighting, I say let them go at it. But in this instance, the girl who was attacked very quickly established her dominance over the attacker. I mean she immediately was in control of the fight. After the first girl broke off the fight, and started retreating, that should have been it. But she retreated not once but several times, and the dominant girl kept after her.
Sorry, but I still think it should have been stopped way before it was. That's what is great about this forum; we can express opinions on the subject freely.