I never had probelms with Pits, but never intended to have one, mainly because of all the negative media crap I'd read. My wife and I adopted a lab mix from a dog rescue group a couple of years back. When we took her to the vet, we were told she was a Pity Lab, with more Pit Bull characteristics than Lab. This concerned us, since we had a little girl at home. The vet explained that Pits were actually pretty good with kids and that being a good dog has more to do with how they are treated than their breed. I'm glad we listened to the vet, because not only is she a great dog, but she has opened my eyes to Pit Bulls. Between having her, the people I've met who have Pits, and the research I've done on the breed myself, I now know this is the only breed I will own from now on.
My thoughts: a dog like this (assuming she cannot be retrained/resocialized) might as well be put down. It's a crime that the owner has allowed this to occur multiple times.
Sometimes an individual dog can set another dog off (a truly dog aggressive pit bull cannot live with another dog at all; the risk to the other dog is too high), or she was feeling territorial. She sounds really dog selective, which means that only a few dogs don't set her off (which can be based on energy level or appearance or any number of other factors). It could still be territorial barrier aggression. The owner could probably take steps to lower her reactiveness, but mostly, it is a management issue.
The biggest thing is, with the history of the dog, it SHOULD NOT have been allowed to happen. There should never be an occasion for the dog to 'slip out'. If you have a dog aggressive dog, you have to take steps to keep your dog and your neighbor's dogs safe. One instance is an accident, two instances are a pattern. You cannot have a dog that you cannot stop for hurting your neighbors dogs.
I was clomped by a Pekingese when I was six.
Menaced by a German shepard when I was seven.
Seen pit bulls go after other dogs while on leash and restrained accordingly.
Witnessed Boston terriers go after other small dogs.
Most dogs I've seen that are tied up outdoors are aggressive. I've now made a negative association with dogs that are tied up.
There are some breeds that I simply won't even consider getting for myself because the breed has had aggression bred into it over generations (dogs used as guard dogs).
And there are other breeds that I simply don't like.
So that leaves me with relatively few breeds to consider. I'm okay with that.
But at some point pet owners have to take responsibility for badly-behaved animals, and get off their duffs to have the animal neutered or spayed, socialized at least minimally, and leash-trained.