Oh, come on! You are recreating the picture to make it appear the Beaver Cleaver family and their little toy poodle Mitzi were the family in issue.
Actually, there was a late 30s man, a late 30s woman, a 17 year-old male, and a mixed mongrel mutt that looked like a pitt bull. There had been a reported felony in progress (wrong call, but cops are damned and sued if they don't treat every call as being based in fact). Meanwhile, cops are getting shot by bone-head "constitutionalists" merely for making traffic stops. This cop reacted in a way that could reasonably be expected given his vantage point.
It's unfortunate. It's a terrible shame the dog was killed. But hindsight helps no one but the nut cases and the John Edwards/Johnnie Cochran tort lawyer bar.
Wrong. The use of deadly force was not authorized here. The cops life was not in immediate danger. The people were on the ground, secured and handcuffed. The dog was NOT in attack stance, it was not running and did not display the typical aggressive signals.
It is a cop-out to say the officer did not know better. He should have known better. He has the power and the authority here, he da*n well better have the responsibility and accountability. And he will be held responsible. If not, then it will be proved again that LEOs are above the law, and no longer hold to their oath to protect and serve the citizens of the United States.