I guarantee that if this dog had attacked and killed a lab/pit/golden the responses would be very different.
As the owner of both a lab and a pit I can tell you that my response would not have changed one bit, and I doubt most of the other posts would have either--especially considering that many of the people who responded OWN SMALL DOGS (and even those of us who don't--a little offensive to suggest that we're all just cool with small dogs getting killed just because we don't own one IMHO).
Personally, I think it's setting your dog up for trouble to assume anything about the dogs that you are going to be sharing your space with. I never do unless we already know the dogs and I have a 65 lb dog that would be much harder to kill than a small one. Accidents happen--they are animals. I know that I am taking a certain risk with Jack when I am going into the park, but he loves it so we occasionally go. It doesn't mean that people who bring in aggressive dogs get a free pass in my book, but it does mean that I have to be very aware that I am exposing my dog to a certain amount of danger when I go to the park.