How did you know he was banned? He never mentioned anything to me so I am not aware, is it possible that he copied something from his own website and was a victim to one of the "bots" that screen the forum for plagiarism? I also doubt he would copy-paste something for the sake of posting, I'll see whats up with him and if he wants to come back and is willing to go through the process of appealing.
I saw the ban tag with the help of the Bpip extension
and the profile information - https://bpip.org/Profile?id=1449095
I wanted to send him a PM asking him whether he was open to the idea of making an appeal if he felt he still wanted to be part of the forum and the ban was unfair, but I wasn't sure yet if a permanently banned account can receive PMs a well.
If you have already communicated to him, then it's all good. I won't send a PM.