The drunk accusation doesn't make sense. I believe Mr Yantis arrived at the scene without a gun, and had someone go up to the house to retrieve a rifle. If he were drunk, I can not believe the officers on the scene allowed him to be handed a rifle.
With what sounds like a lot of observers on the scene, I am quite sure the officers sole duty when Jack Arrived was to ask him to dispatch the animal,while they observed. Still confusing about him with the rifle mounted and ready to shoot and an officer grabbing Jack while he was "hot to shoot".
