Others have said they have had this happen on other servers, but wanted to throw it out to you anyway.
When I logged in I was not on my team (Scourge admin names). Instead I was in a group with a few other players on Scourge. I asked in chat and Phat Boii didn't see me listed on their team at all.
When Mackinnonandrew, Majin and RepeatPete logged in (at different times) they also had the player team names as below.
Had to drop team and start new group to fix.