The video shows nothing.
I understand if you attack them, then they will get heavy handed with you. Fine. But to beat someone who is not trying to attack you is excessive..
If they ask you to comply and you don't then you are showing signs of force and they have every right to neutralize the issue. It's not like the beat him with a club or maced him. You can tell he's trying to pull away the entire time so yes if his arms are bruised he deserved it. It's not like he was doing this to some local mayor he's lucky SS didn't drop his ass after he started a scene.
Seems to be very easy to find similar stories from Australia.
Restrain him. It's not hard, and the officers are trained on how to do it properly without having to beat the guy.
If you are on private property in a venue like that and you don't follow the rules then yes you should have your ass kicked for being a douche. It's no different than if you stood up in the middle of a movie. Who cares if you don't say anything you're causing a disturbance and you deserve to be asked to leave. If you don't comply then you deserve to be beaten with a flashlight.