I understand your point, but you did unintentionally bring up the unlikelihood that the dog was charging to attack. The reported circumstances overwhelmingly suggest that the dog was standing and barking, not charging to kill. The odds are very poor that Mellerstig whipped out his gun in a panic and hit his target in a fraction of a second. Possible, yes, but extremely unlikely. It is vastly more likely that the dog stopped and barked, giving Mellerstig plenty of time to think and aim. The widespread assumption of a charging killer dog is the least believable scenario.