According to this new line of argument, if an armed burglar broke into your home in the middle of the night and you directly encountered him, you have no choice but to throw down your arms and flee for your life because that's what a "reasonable person" would do.
I can't go along with that. I would say these attacking dogs were like burglars armed with knives. In some ways, they are even more dangerous, because they can't be reasoned with and they were already in the process of killing something when found. A burglar, when found, would only be digging through your stuff looking for something to steal.
Furthermore, let's imagine that we were not talking about 2 attacking dogs here, but one day you come home and a tiger is in your house. Maybe you could run and make it. But maybe you couldn't. If you somehow managed to get to a shotgun and kill the tiger in this unlikely scenario, I doubt you'd have to worry afterwards.
So how are the dogs different than a tiger? The only difference is their size, and whether or not you give a damn about someone else's dog. I think a "reasonable person" could make the decision to shoot the attacking dogs.