"SHOOT HIM?"
Remember, we're going to let everyone speak their mind without getting after them. The point that I'm trying to get to, is that there are many different responses to the exact same description, even among very experienced dog trainer/owners.
In this particular case, the description that the gal gave me, was very puzzling and odd - there was no overt growling, but the dog kept advancing on her without showing any friendliness, any tail wag, just a very direct look, and yes, she felt it challenging.
She got a very, very odd feeling from the dog. She isn't a trainer, but this approach made her distinctly uncomfortable. She said it was behavior unlike any dog she's ever seen in her entire life. No indication of friendliness, yet not clearly growling either.
She did believe that the dog was the same one that had been involved in the bite incident; she didn't know the circumstances of the bite incident.
We have many loose dogs in my area so I was very curious as to what you folks thought.
Our tactic is to put up a very high electric fence, though we feel a determined dog could still get in.