The same thing happened to me just a few minutes ago.
I queued as a healer, accepted immediately.
At that time I was watching a movie so I alt-tabbed (during the loading screen) to pause it. That action (to my mind) gave me a loading lag for 30sec.
When I tabbed back I saw this picture: loading screen fot the jade temple, a sec later pandaria loading screen and a note 'you have been voted ...' = deserter debuff!
How Is This "Working As Intended" Situation?!