the destination will cause it to get stuck and become unable to move or attack.
The only way it can still harm you is if you run into it on purpose to kill yourself due to the +SPECIAL flag.

As shown here, I used "am_cheat 3" to display every actor's collision/bounding box.
Edit: I looked at the map in an editor and there are actually 3 teleporting lines and destinations. The faulty one is line #271, and the teleporter destination in question is thing #47.