If the dog wasn't behind a fence, or wasn't on a leash or chain, it was loose. Maybe not "running", but loose nonetheless.
So, dumb question for you.
Let’s say the dog was behind the fence, but not chained. The officer enters the property and the dog runs up to him and “confronts” him. Officer shoots and kills dog..still justified because the dog was “loose?”
Why is that so different in your mind?
The officer did one thing to “provoke” the alleged confrontation...he was walking across the front yard, not the sidewalk.