Apparently the last elevator in ERZ2's right path can be triggered twice if another player is inside and steps on the arrow. Me and a friend achieved this on accident - he stepped on the arrow, triggering the elevator, and I stepped on the arrow while the elevator was moving. The elevator's animation then restarted, and while he got teleported to the correct room in the end of the level some time after, I got teleported to somewhere out of bounds and had to suicide.
