Banned unfairly

I was banned at about 11:25 CDT from the official Undertow server for "Griefing and helping a griefer" (Name Osama Bin Laden) even though I had just played more than 5 games in a row, all where I actively helped stop griefers and played the game fairly. I believe this is due to a friend who was also in the game with me (Muhammad) saying I was griefing AS A JOKE. Many people in the server could definitely vouch for me, as I was not griefing. To make matters worse, I was kicked right after I had been killed by a griefer who rdm'd me and 2 other people.
The ban is only 8 hours, though this is still unsettling to know I could be banned at anytime, just because 1 person said a joke, even after playing multiple games fairly, not trolling or griefing.