This is a slippity slope, isn't it? People really freak out about animals. They love them so much, that even hinting at dog murder could get me in a dog bowl full of hot water.
I guess my initial response is, depends on the man.
This is telling, because I don't care if the dog is an asshole or not. Dogs are dogs. They don't have the capacity for evil. They just shit and wag and eat and cuddle. Men are terrible, awful creatures. So in most cases, my answer would be, shoot the man.
But to be clear, I'm not so soft that I think animal rights should be placed above human rights. Sometimes when people soapbox about the mistreatment of animals, in the face of human starvation or lack of funding for social programs that benefit the poor, I cringe.
I suppose I'm a contradiction. I believe that human life inherently has more value than animal life, and yet, I don't like most humans, and I do like most dogs.
Short Answer: There. Honesty. Wait, why am I shooting them? Is this a standoff at the end of a movie? Is it one of those setups where the dog and the man look identical, and I don't know which one is the real dogman so I don't know who to shoot? "You're barking up the wrong tree! Wag the gun that way! He's the dog-poster!" I get it now. I'd be all like, "I know that one of you was neutered. Pull down your adorable pants and show me your dogman crotches! Right now!"