The difference being your dogs didn’t cause any problems and are about 40 pounds. I love my dog like a child and the same goes for other all other animals, but that being said I have neighbors with ill mannered dogs and if one of them got loose into my yard while mine was tied up and attacked him I would shoot it without a second thought. So I guess a good way to flip the question is say a 90 pound pit or GSD attacked your wife and was causing her bodily harm you wouldn’t do whatever is in your power to stop it? You and other people may draw a distinction between the 2 scenarios but a lot of people do not. It’s still sad the pit was put down, but given the circumstances I understand the guys reaction.