Normally, my rule is “If it hurts a human being, it dies – and so does everything that looks like it within a mile radius.” This rule has served humanity well, and I see no reason to just abandon it. But when the critter that you are hunting takes your own gun away from you and shoots you with it… well, sir, you have let the side down.
Not only should the fox go free, it should be found, given medical treatment – and presented with the man’s firearm. Only then may we extirpate the shame brought upon us by this unfortunate episode.
More here.