I remember one case just about what the OP is talking about. User shasan temporary banned and as far as I know, his problem was solved somewhat faster than usually just because of his lending business.
also, he only ended up with a signature ban, which is an acceptable minimum penalty.
His ban appeal thread
https://bitcointalk.org/index.php?topic=5144331.0I recalled one case did not have signature ban. It means after a successful ban appeal, he was free entirely. Don't remember who is so lucky.
I checked theymos' post history and chimk is the case who was mistakenly banned and his ban appeal was accepted. He even got his signature space immediately after the appeal approval.
First of all, if you have a history of good posts, then we're going to be suspicious of any plagiarism accusations. Second, if it does happen, you can come to Meta on a new account and explain it.
That exact scenario happened with chimk, and he was unbanned after we found out. And although it was certainly a big mistake on our part to have banned him in the first place, the person who framed him did in in a pretty sophisticated way, and his case was exacerbated by the language barrier (eg. we were unable to immediately determine whether he was a good poster or not).
No, because mistakes are occasionally made. chimk was framed that one time, for example.