Just wait.
Alright this sounds like a completely logical reason.
Now here's the thing, I wasn't roleplaying while I was loading. All I was doing was amusing myself while the files downloaded. There was no issue with my name breaking the immersion of other players because I wasn't in game yet and I wasn't going to roleplay when I joined.
All I joined to do was view the build and leave. There's no reason why the name was an issue to other players.
The reason he banned you is
1) Having someone walking around shooting absolutely nothing while getting wailed on by zombies and never responding to other player's requests and just checking out the build and picking up all the guns which is unavoid able and blocking passageways-
forget me, too much to explain. It breaks the immersion, plus people are going to think stuff when they see,
"SeventhSandwich is now named captain handjob."
2) Secondly it's a loving role play server. You're not there to look at the build, you're there to RP. If you're not there to RP, you're doing it wrong.