Kelly, I just saw this thread (was out of town for a while), and I'm sorry you had to experience that. What a horrible way to end up leaving a job as well, and even worse that you didn't receive any sort of apology/compensation from the owners of the dog.
As for banning Pit Bulls, they are banned here in Toronto, meaning they are not allowed to be kept for breeding purposes (all existing Pit Bulls must be altered and are to be muzzled at all times), although I imagine backyard breeding will still go on, and those are the people we DON'T want breeding Pitt Bulls.
Last October, a friend and I were walking along a trail near a ravine where I live and we came across a bony, battered Pitt Bull mix (likely Lab) and though he was quite afraid, we got him to the Toronto Humane Society. He had a lot of puncture wounds all over his face and body, likely from another dog. The THS took care of him, neutered him and waited to see if he would be claimed. Nobody claimed him, and ultimately he was adopted. He was a very sweet natured dog, but how can it be determined that once he was healthy he may potentially turn on his owner?
That said, I know of a family who had 2 Pit Bulls. One was very good natured and never hurt anyone yet the other attacked and nearly killed someone, and the dog was put down. This is where I wonder... If one dog is good natured and the owner treats both well, where does the other pick up this instinct, seemingly to kill? There could be more to the story, but this isn't the first instance I have heard about this.
In addition, my brother was badly attacked by a Beagle when he was a small child, and the same owner's Cocker Spaniel nipped at me once which was kind of scary. They also had another dog many years ago who was very unfriendly, so I imagine in this case it was likely dog owner vs. dog breed.
Personally, with all of these observations, my opinion on banning the breed has evolved somewhat (I used to vehemently oppose banning the breed, especially as the Toronto ban happened concurrent to finding the dog in the ravine), but I do feel there needs to be some firm legislation in place surrounding the issue of dangerous breeds, their breeders/owners and backyard breeding for all states and provinces across North America.
I also feel dogs should be leashed at ALL times, unless in a specific off leash area, where people would expect to find dogs off leash. I have often felt my heart rise into my throat when I see a large dog suddenly standing dead still a few feet in front of me with an owner nowhere to be seen, while walking on the trail in the ravine near my home.