There was a "crazy" German shepherd, Heidi, that lived with its owner across the street from our other house. She would run over whenever we pulled into the driveway and bark at us and bare her teeth. I was afraid to get out of my car.
Eventually, we decided to talk to her owner but asked him to put her in the house. After we got to know him, he let her out. Since he was relaxed about us, so was she. After that, she would still show up in our driveway, but now it was because we would play fetch with her. She was so beautiful and graceful and fast.
The owner was playing with her in the back yard. She was fetching and tripped and fell, and broke her leg. She was never the same after that---it seemed to take some of the spirit out of her. But she was still always glad to see us.
She would still escape off her leash and frightened a worker at the office across the street. The worker called the pound. I raced over and told them that I would keep her in my house until her owner came home. I begged them, I cried. I did not want them to take her.
They put the noose around her neck and captured her. I pleaded with them...they were probably doing their job but I felt like they could have left her with me.
After that, I never saw her again. I talked to her owner and he said that he had found her another home out on a farm. But the way he said it had a tinge of sadness that made me feel uneasy, like he might have left her at the pound. Even now I can't bear to think about that, but I never would have been able to keep her either, since I'm downtown on a busy street corner.
My point is that I think 3D's solution is a good one. Kill him with kindness and get them aquainted. I still wouldn't trust the guy alone with a dog, but he might have been traumatized by a dog sometime in his life, you never know. It's worth trying to resolve it and then maybe the barking would stop and everyone would be happy.