Alternate Everquest

I've encountered this behavior as well, particularly in Dulak.

Once the NPC reaches the threshold to begin fleeing, it appears to warp under the world, then appear a short distance away, usually in a place inaccessible to players.  This begins the long path of trains that will usually arrive around 5 or 10 minutes later, depending on how far away the fleeing NPC gets before reaching another mob to share social agro.