That was a pretty ugly video.
But I take some exceptions; the police didn't arrest him for violating the store policy, they arrested him for obstructing a police officer. I suspect they will hang a "disturbing the peace" charge on him if the woman manager's decription of events is right. Having once worked at a Wal Mart, I very strongly suspect there will be a video of that part too, taken from an overhead perspective.
In most jurisdictions you are required by law to I.D. yourself, atleast tell the officer your name if you have no physical id. That is probably the genesis of the problem in the video.
I. M. O. he should simply have left at the beginning of the event rather than getting upset. I don't know what the local law is concerning I'd for liquor , and id'ing spouse and kids seems unusual and absurd, but if it is store policy, the remedy ought to be to go to a different store.
I think --- again, if the store manager is correct -- the vet has anger problems.
Another issue: you don't argue with police, you don't tell them they need to be retrained, if you believe they're in the wrong, the hill to die on is in a courtroom with a lawyer to represent you. The vet was claiming rights that he did not really have, or if he did, were not going to be acknowledged at that point, but later in the controlled surroundings of a precinct house ..... or in court.
It did seem to me the police were overly aggressive in the conclusion of the video ..... why they had to do that could certainly be questioned and if his disabilities were exacerbated then I smell a law suit in the making ....
but if the manager was going to press charges some type of physical compulsion was inevitable.
I feel bad for the guy, and if I'd been watching it live, I'd probably be pretty upset about what I was seeing. The police were tough in the end, maybe unduly so, but otoh the vet prolonged the incident far longer than it needed to be: in that respect the police were pretty indulgent.
Sorry if my conclusions are different. I'm not trying to be antagonistic.
The police may have been wrong in the way they subdued him .... that's for a courtroom. But, the bitter truth is, the vet initiated the process in how he acted. Just my opinion, IANAL.