I believe Dylan took extreme liberties with that story also.
I like Bob a lot, but he liked to go for the emotional response, as an artist tends to do. He's not historian.
He said he got a lot of his political info back then from his girlfriend Suze Rotolo.
That was a time when many black men like Carter were supposedly railroaded into jail. At least many white libs like Dylan swallowed those stories. I read Carter’s ghostwritten bio, which contained a number of stories of which I was extremely skeptical as to their veracity. I don’t know for sure if he did the crime he was put in prison for or not, but he was a violent person in and out of the ring.