Knowing both parties involved personally and I am not his room mate. I know they weren't cheating. That means nothing to the Immstaff or anyone else in the playerbase which is fine.

When I am at his house I play from a proxy just to prevent this kind of issue but that is me. The problem comes from the fact from his point of view everything was legitimate. From the Immstaff it wasn't. They were doing their job to try and make the game fun.

The problem is since he was following the rules and has been for a long while. He likely feels as if he was judged as guilty without any form of due process and that is exactly what happened. Circumstantial evidence is what you had. He got a warning AND a punishment of having to use OOC knowledge to avoid a character in game even though he did nothing wrong. Yes you didn't shoot him in the face for it but you spit in his mouth.

Did either group do anything wrong? No. It was a misunderstanding that was likely mishandled by both groups. It makes people who legitimately follow the rules to ignore them. On the other hand cheaters make it hard to believe for the Immstaff that this was just an innocent mistake.