Well, only three things I can recall.
When I first got my admin sometimes I typed messages meant to be for Admin chat in All chat by mistake.
There were 2 times when I was an admin that I played drunk, but only one time I made a mistake. I was the only admin in the server because it was like 3 AM and I kicked 3 AFK players on my team instead of switching them to spectators. My reason was "AFK for lnoger thann 10 mnutess" (the spelling was something like that, haha).
Oh, another was saying "Jack@$$" over the mic....yeah, no more admin after that lol.
xD