On a few occassions, yes. Moon Patrol - Archer's Line. During the public event "Defend the Warsat" when mobs come out of the caves. Not a common occurrence but one of the first places I've first come across it outside of PVP. I farm this area usually for filaments so I can say it didn't happen before. Earth Patrol - Skywatch. During the public event "Defend the Warsat" as well. One of the ships dropping mobs did a similar warp during drop. Only seen this the one time (but I think I've only done this event at this location 2 or 3 times overall, so not much to compare). L28 Weekly - Summoning Pits. Just did it last night. 3rd wave when opening the door to go down to the Pits and you have a bunch of Wizards which will chase you up the staircase. Wasn't as bad as the public event though.