I've met more mean Labs than I have pits. It doesn't matter what he is or isn't. Neuter him, train him properly, and train the kids how to behave around dogs. Any breed can be nasty to kids. Prime example: chihuahuas. There's a reason why vets, vet techs, groomers, and kennel personnel groan inwardly when they see one. It's just that a chihuahua attack doesn't make good news headlines. Neither do all of the minor fender benders. But of there's a dead body laying in the street, hold the phones, this is breaking news.
I live with 11 Arabian horses, and people sneer about what horrible hotheaded horses they are. Again, I've met more jerks of the quarter horse breed.