devtrackers.gg
You can appeal that one via this link.
Too bad you weren't watching his stream when he was banned. Might have gotten unbanned 5 years ago.
The account is yet to be reviewed recently via that process, where it should be based on a few factors - namely the offence is very old, so more in-depth investigation is required - something which should be logged and checked by our appeals team in this case. I'm not trying to make things difficult here!