Today a friend and I were playing some Infinity Slayer on the map Complex when the enemy team decided to capitalize on this glitch where you can jump above the door frame in the lower level of the building in the corner. While they were in this glitch they were unable to be harmed and could emerge whenever they wanted to.
At first we though that this was our fault for knocking them in there with grenades but after watching the replay in the theater it is apparent that they knew about this glitch already and were entering it in their own. I have video proof of this on my fileshare.