Doesn’t matter if the leash broke, the gate broke, the dog jumped out of the car... at the time of the incident his dog was secured and hers wasn’t. And killing a small dog isn’t hard for a Germans Shepard. Now if the dog killed a kid, or grabbed her leashed dog through the fence, or had a history of biting maybe there would be some concern.

But for this instance he really doesn’t need to worry. It’s basically like self defense, the dog is allowed to defend itself from another off leashed animal.

Now I’m NOT saying it’s good to have a dog kill another dog. And I’m not saying he shouldn’t be working with/training. And perhaps he should use a basket muzzle when out now with his dog now that he knows what it can do.

I’m only responding to the legal question of liability which he is fine on.