Right, so we were doing ToGC 25, and something strange happened. I was feared outside the arena on the faction champions encounter.
On the first screenshot, you see I am soulstoned and out of the arena:
Now, I walked a bit further(south from where I standed). Then I falled through ground. However, I could see the room where Anub is, but I landed somewhere else. While I was falling I saw multiple rooms I could land in, this is the one I landed in (glad I has soulstone :-)).
Also, there was a path to another room, but I didnt have time as I was raiding
Hope you enjoy!