This has what the Leftwing policies in schools have wrought upon the system. A lot of written BS policies and talk of zero tolerance and such thing coupled with Reams of Red tape that can't be enforced because of the lack of Teeth or Fear of consequence from those who scoff at the lip service without the muscle or will to back it up.
It was a example of Pure human nature, everyone sat and watched because clearly the girl taking the beating was outside their circle of Friends and Family. The half hearted effort by the Teacher made me roll my eyes.
Back in the Day this would of at least taken place after school off school property. Now it's just part of the show in the land of public education.