This line from the article:
"One minute she said he was patting the dog and the dog’s tail was wagging and the next, the dog had Mitchell’s head in its jaws."
She also mentions they looked away from the dog & child to look in a freezer.
I am not making excuses for what happened.
But there are about 14 different tail wags and only 2 of them mean a dog is genuinely happy, assuming the rest of the dog's body language is saying the same time. People need to stop focusing on the tail and look at other body language. Don't let your kid stroke dogs they don't know, or approach dogs they don't know, regardless of what the owner says (because 90% of people can't read their own dog).
I feel really terrible for the child that this happened.
It really shocks me how many dog owners are completely unable to read their own dogs. We were on holiday once and in a pub. The owner (of the pub) was telling everyone about his wonderful serbian rescues that were now pub dogs. Both appeared. The MOMENT they looked at my toddler DD (walking about) I told DH (next to her) to pick her up. Everything about their body language said "not happy" and they went straight in to very hard staring, which is just a few steps away from snapping/potentially biting. The second one did the same thing to my dog once he looked at him.
I told the landlord that his dogs were not suitable to roam free in a pub and we promptly left.
Not enough people have any idea how to read dogs. Equally, there needs to be changes to laws around dog control, and how easy it is to have & own dogs.