I hear all the uproar, and there are simply of couple of issues rolling around in this head of mine.
First, I think getting focused on leash laws was a diversion, because it isn't the leash law that is at issue. The issue is any person (not just LEO's) has the right to defend himself against an attacking dog anywhere he has a right to be. There are two key nuances in that statement. First, what is a reasonable person's interpretation of "attacking dog". Second, the issue of whether they have the right to be on a certain property.
Let's leave the property issue alone for a minute and look at the scenario of a stray dog unaccompanied by an owner running towards you barking aggressively while you are walking in the park. Nowhere does it say you have to let yourself get bitten first to see if the dog is really attacking or just barking. That situation can happen fast. I could see myself going from recognizing a bad situation to actually shooting at a dog within 4 seconds, so the elapsed time on the video does not seem surprising or unusual.
Now, let's look at the property issue. Regardless of the right address or wrong address, that officer had the right to be on that property. He was responding to a call at the address he had been given. You cannot fault the officer for being on that property since he had a right to be there, so the whole "private property" argument falls apart.
As far as gun drawn, we heard a couple of shouts for "show me your hands". Obviously, the officer couldn't see his hands or he wouldn't have been shouting. We don't know exactly when he pointed the gun at the homeowner. For all we know, he had his hand on his holstered sidearm, or he had the sidearm at low ready, until that moment he had someone coming towards him. When he transitioned to actually pointing the gun at the person is a big unknown. So we can debate our suppositions endlessly, like other recent cases in the news, or we can simply admit we don't know what that officer was really facing.
Lastly, I was also struck by the thought that when it was all said and done, that officer did go home safely to his family at the end of his shift. That isn't something to be taken for granted and minimized by people using 20-20 hindsight.