LW should have absolutely told them "I shut my dog up in the other room because he doesn't like children" but because so many dog owners completely suck the parents should expect that LW will be no different and just automatically keep their toddler away from a dog. And all these adults need to educate themselves on what a stressed dog looks like because, again, that bite did not come out of nowhere. The dog almost definitely indicated "Yo! I am not happy! Get this child away from me!" before biting.

There's blame enough to go around.