No, because what is the well-worn phrase we always hear?
"He's never bitten anyone before, he's such a gentle dog ..."
I should bloomin' well hope he HASN'T bitten anyone before, but as in this casae, just once is enough.
Borth breeds are known to be in the upper end of the 'pack' mentality, and they will challenge for their place in the hierarchy if a newcomer seems to be a threat. With either breed, if one starts, the other will join in, that's nature.
It's so easy to say you should never leave a tot within reach of any dog of any size, because ANY dog is a potential child-killer if it decides to act on the threat to its pack place.
But it's a fact, and this poor family have learned that simple lesson in the most heartbreaking way possible.
My heart goes out to all of them, but no, people will never learn.