Boeries and Rotties have a vast range of personalities. Jasper was not friendly with other dogs. I remember standing with him in the dog school while they sit in a row. Then some dude brings out another dog and lets him sniff the first dog in the row from head to toe. The first dog was already trained but the concept is for them to learn the behaviour of remaining calm. Jasper and me was last in the queue and I was panicking more than him.
The dog finally arrives and starts sniffing. He didn't like that for one second

. Eyes bulging, teeth showing and back hair lifting up. He didn't move but he didn't like that one bit.
I still believe a level of responsibility is required and all this who ha of "my dog will never bite a kid" or something is exactly why we end up with stories like this:
Might be the friendliest dog in the world but I can see from his stance and the kids movement that this isn't a good situation.
Never around kids without me around. Both to klap the kid if he does something stupid like smack my dog's face and to have control over the dog since they are still animals.