"But cops only get to arrest, NOT PUNISH."
The police were tying to get him to comply with verbal instructions. The knucklehead refused. The police persisted in trying to get the guy to comply. I don't view that as punishment.
Now, if they thumped him while he was in the squad car, that's punishment.
"They should have arrested and removed him, if he had done something to deserve arrest."
He was trespassing and refused to comply with a police officer's orders. He deserved to be arrested. The police then arrested him and had him removed.
Sorry, I call BS on that.
Once he is in cuffs, he is, technically, in custody, and the responsibility of the Officers present. Tazing him for not standing is going to be a tough sell to a jury when this gets to court. If three officers can't pick up and haul out a 90 pound punk with an attitude, then there is something seriously wrong. The first taze might have been justifiable, but by the fifth taze of a suspect in cuffs, it was outrageous bullying.
Lick much boots lately? How bout I tase you a few times and command you to get up?