It was. Read it again. Dog was shot on it's owners property. If it had left the property, you'd have a point. As it is, you don't...
There was apparently an INVISIBLE fence. Until this thread, I didn’t even know what an “invisible fence” was. If people can’t clearly tell that your attacking dog is confined ... it isn’t as confined as it should be, and you run the risk of people overreacting to an apparent attack.
SnakeDoc