Although you're right and I do not condone shooting a wandering dog, it is the owners responsibility to keep their animals under control. There is no reason why your dog or anyone else's dog should be trespassing on someone else's property. If your buddy were more responsible and taught the dog to stay in the yard, this wouldn't have happened.

I feel this way because I own a farm where we raise cattle and raise a few deer for hobby. My property is not near any houses do there is no excuse why there should be dogs running my property. More than once I've come home to my deer slamming themselves against the fence in shear panic because some unresponsible owner's dog things it's a fun game to chase them around the outside of the fence. I have some pretty nice bucks that are tame as dogs that I've become attached to, and needless to say Mr. Puppy was introduced to Mr. 22-250 before my buck got his neck broke. Same goes with them chasing the cattle. Pen up your dogs or get a shock collar and you won't have any troubles.