The citizens will pay first (literally), then I hope, the elected officials if they cover this up or let this guy off easy.
Well, had I been the shooting officer's place--and I acknowledge that the stop was poorly supervised and out-of-control--I too would have shot the dog. I don't think the officer had much reasonable choice at the time, things having decayed to the point they did.
I, rather , think the responsibility lay with the on-scene supervisor or senior officer.