I have to admit that I too would just love to bash the police.
But,
In this case there is some evidence that a minor mistake was made that shows that it was an accident.
If you look closely you see the invalid before the incident leaning forward and putting the brake on the left wheel, and he no doubt put it on the right wheel also, but the camera does not show it. This is proper wheelchair procedure, done automatically by any care giver or the patient himself.
The photos are not continuous like a moving picture, but are a series of still photos.
The attendant, deputy or policeman, pushes on the chair, but the brakes are on, so he pushes harder and tips him out.
Any caregivers, out there, that have a knowledge of wheel chair procedure that can corroborate this?
belbab