First, thanks for reporting this player in game! This is the best way to go about letting our security team know of these types of issues.
Now, in regards to the actual issue you encountered, how many times have you actually seen this occur in game?
Theres only going to be 1 more patch for the game, after that Ghosts comes out and the enforcement team goes bye bye. Unless theres enough complaints about this, nothing will happen. All minor glitches will remain in the game.
Sorry for the late response. I only experienced in the 1 game I mentioned. It was 2 players in the "hidden" room.
I have done the glitch myself on PS3 but it gives you no advantage at all you can only see players in the top corridor and even then you cant shoot them but they can shoot you.
The one time I saw someone doing it they had light machine guns and did shoot through the room. Do you think they had FMJ? Also it was 2 of them in there on opposing teams. I guess they felt safe to boost hidden in the hidden room.