I think there are two issues on this level. First of all, the cops could have heeded the Smoaks, taken a second and simply closed the car door, and nothing would have gone awry and this story would never have happened. And second, I think the cop who shot the dog probably overreacted. What should come from this is better training of police to quit being full-blown hardasses in every instance, and think a bit more - with all three people in the car handcuffed, and the number of cops on the scene, they could have done a much better job here.
But as I see the video (102), the dog looks to me (as I said) to be pretty much in the cop's lap when he shoots. Othrwise, check #140, if you haven't already.
Dan