We have a pit bull in our area who, so far, will take your face off at will with her tongue. She has been so far the sweetest thing that walks on four legs. But you can also see, by how shy she is, someone has mistreated her. My guess would be because she is allowed to roam many have driven her away, hence the shyness.
Our neighbor had a male pit pull that seemed to be great with that family, until one day. That dog was out and about, walking around the neighbor's yard, when another dog appeared down the street. The neighbor's male saw that dog and it was like that male had been shot out of a cannon when it took off and attacked that other dog. Both dogs may have been fighting for about 10 minutes before someone finally decided it needed to be broke up. And it took maybe another 10 minutes to break up. No one wanted to get in and grab either dog until they were separated, but no one could get them separated. There were about 5 of us there, some from the neighbor, the other dog owner and my self. I'd been working in the yard with a shovel so I took the shovel and put it between both dogs and started prying. Others grabbed the pit, the owner of the other dog grabbed their dog, and everyone pulled. Once they were apart, and controlled, it was over.
It was obvious the other dog did not want to fight in the first place. When it saw the pit it took off in the other direction. And all through the fight it fought more of a defensive battle. Although it had bite marks on its face and nose, like the pit bull, what saved it was the long hair it had. I watched the pit bull try several times to bite that dogs throat, but it couldn't because of the extremely long hair.
The neighbor made the mistake of allowing their young daughter try and control their pit bull. Mistake #1. The dog was allowed to be off a leash. Mistake #2 many around here do. And the fight went on too long before the neighbor's family, and the owner of the other dog, got into action to stop the fight. Mistake #3.
I've seen pits that will lick every freckle off you face, and I've seen some I wouldn't turn my back on. I've also seen other breeds who were the same. That article is spot on when it says the owner must take control and keep it. A dog is a pack animal, and the owner must establish their Alpha roll as the pack leader if any dog is to be, not necessarily controlled, but kept in line.