So you know he's not cheating because he got banned on a koth server many years ago, we're not sure which one, not even sure it was a koth server, only that his account was banned for hacking by a server using a better anti-cheat 5 years ago. And now, 5 years later, he has a different IP address... Guess you got me. IP addresses are like social security numbers; you have them for life. And it's not like they can't be proxied to disguise region.
This really is the "Sorry my brother took my phone" argument.