Gm's ?
For the 2 times i've been banned, i just got banned right now, they were both in fireteam & while i was Opking' id happen to come across this person who stands still and u cant see their nametag or anything, its like there not even there, and for those 2 times, i Got a connection to server has ended, coincidence?
i never met a GM before so i wouldn't know
but it sounded like you got trolled.
There is a GM in nearly all Fireteams and Qr, especially in the Black Market section, there are GM bots which are invisible.