as I said, I would also defend myself, and I would be very upset, infuriated, if my dog were to do this to someone. the problem is that 99% of people Ive met think my german shepherd wants to eat them alive when he is wagging his tail and begging for an ear scratch. and actually baring teeth, snarling, and hair up on top of back is a fear response. dogs show do this to people if they are cornered and afraid of the person. if a dog is charging at you he will look the same as a happy dog begging attention. cats are the only mammal with the ability to move their tails independently while running. dogs cant wag their tail while running, they can hold it straight out (or curled if a malamute, akita, etc) or between their legs. the only main difference you can tell between a angry dog and a happy dog running towards you is the happy dog will most likely be moving slower, possibly wiggling its body and head held low. head held striaght out (whole spine in a straight horizontal line) ears forward, eyes locked on yours is a predatory charge, ie a wolf charging towards a moose.
please dont take this the wrong way, I am not trying to convince anyone to ignore a dog running towards you. as I said, I would defend myself. unless it was rabid or attacking (or had before) a person or child I would not shoot it. I would kick, hit with a stick, etc. but yes it is better to shoot first and deal with the cinsequences. and I absolutely believe that no one should be allowed to own a dog and not have absolute control over it. name a situation for me and I garauntee one of two responses...either "yes, I'd have complete, total control over him in that situation", or "I dont know about THAT one, havnt trained in anything similar and therefore in that situation he would be on leash". so do I hate anyone or have anything against anyone who says they would shoot the dog? nope, not at all but I do have something against the owner and if they try to sue you over that, they should be thrown in jail for allowing the dog (truly dangerous/aggressive or not) to run loose.
the only reason I asked if anyone could tell the difference and detailed, somewhat, the physical and noticable differences between agression and "oh boy am I happy, please pet me" is so hopefully, atleast assuming the dog is charging from a distance and not from 10 feet away, you might have time to look and recognize if its a threat or not. do I expect everyone or anyone to see a dog 60-100 feet away charging for them and say "hmm, maybe I should leave my gun in the holster cause I cant tell for certain"? of course not. but hopefully it will help you, the owners, and the court system. doubtfull but as an animal lover, and a professional dog trainer (obedience, herding, tracking, agility, protection) I have to try. to me a dog running towards you is no different than a person running towards you. you have to think and evaluate wether it is a valid threat. just like with a person in a parking lot, could be in a big hurry to get to their car and run right past you. the dog could be after a rabbit you didnt see, or a ball you missed, or heard its owner calling from around the corner but has better hearing than any person so you didnt hear it. anyway, I'll shut up now.