How exactly should they have "tested" the dog for rabies when it came in?! Since they can't do that without killing the dog, I'm not seeing the problem here...

Not giving him the rabies vacc was a dumb move on their part...however, if he was already infected it wouldn't have done any good, and there is no way to test a living animal for rabies. Killing every animal that comes through the doors to dig through their brain is obviously not a viable option. Having a better quarantine period for observation of adoptable dogs would be.