I agree in that they should have left, the force used may have been excessive. Personally I would have asked him to leave and when he refused I would have informed him that if he doesn't leave he'll be arrested for a breach of the peace if he then resisted he'd have been restrained and cuffed. I found that worked well when dealing with arrogant people like that guy. Lets not chat too much I'm telling you to leave if you don't you'll be arrested. Most people then leave.
I don't think for a second that these guys weren't given the chance to leave several times. The police always give warnings about what's going to happen, especially in a place like a supermarket where the cameras are rolling. These guys just wanted to needlessly argue and cause a scene. They weren't leaving until they were nicked, imo.
The copper calmly tried to lead him out of the store by gently pushing his back in the direction of the door. By this stage the gobby chap had decided that he was going to play up to being filmed and dig himself a bigger hole. "I know my rights I can film in a public space" Tescos is not a public space and they can ask you to not film inside their stores. "Don't touch me , you have no right to touch my personal space" The officer has every right to use reasonable force to remove the guy from the shop. When he pushed the policeman away he cautioned him and forcibly arrested him and his shrieking wench , they both resisted arresest which is why they ended up wrestling on the floor and crying. Lying about being punched by the copper won't have helped things either. Act like this to police in most countries and you will get beaten . Zero respect for the store manager zero respect for the police .
Hard to see and hear what was said at what point, personally I would have made it clear what is going to happen before it escalated. Spelling out what will happen often removes the problem.
Shouting "He's dead" whilst eating the polished floor was not a great idea if you are getting your mate to film you .
Their attitude is terrible from the start, making an issue about nothing. I may have handled it differently when I was in these situations but from what I've seen I don't think they would have listened and force would have been used.