I was slightly shocked on two occasions:
When Mr Polumbo decided on a whim that Lemar should come in on strike day and ignored the set out behaviour policy. My partner and I work in a school for boys with EBD, if we made up consequences on the spot the boys would (rightly) go nuts.
And again when the deputy head (I think) couldn't see that Halil was obviously so ashamed and upset at his behaviour and misread it as anger/disrespect. He was given about 5 seconds to look up and apologise. That just isn't long enough at 13/14.
I think the previous poster is right; it was all escalation and no descalation.
Also when Mr Polumbo went up to halil afterwards to rub salt in the wound. He was bent down right in the kid's face. So confrontational. Where I work that would get you a swift box to the side of the head.