I'm not sure I'd go that far. They blew it--yes. But they have been under extreme duress for over a month now, and they were undoubtedly at their breaking point. There's no telling what they've faced following Katrina, and they were probably a little trigger-happy because of it.
I'd say a short term of suspension without pay, lots of training in "necessary force", and of course, monetary retribution to cover the man's medical expenses.
I'd hate to make excuses for police behaving this way for no apparent reason. Makes you wonder what happens off camera if they are so bold as to do this knowing it was being filmed.
I just don't think police like this are an asset to the force.