People shouldn't be irresponsible with leaving their kids alone with dogs, especially those with puppies! It's a really sad situation for the dog and the little boy. People forget sometimes. I remember when a child in my neighbourhood was walking the family lab on a leash in her front yard (parents not outside) and I go to leave my house with my dog and I have to worry that the lab is going to pull her right over trying to get to my dog. I don't allow my kids 10 & 6 to walk my big dog, because they don't have the physical size and strength to handle her. Even a very well behaved dog can all of a sudden see a cat or something and then the kid doesn't have a hope of hanging on to a dog.
On the other hand, I don't think too many people can say that for a split second ever that their dog is not alone with their kid. I don't think anyone follows their dog from room to room all day long! Obviously with puppies you would need to make special accomodations, but I dont' think it is always fair to blame the parents.