i have done the quest fully a few times...
his spawn time is not random, i have been timing it and he has been spawning on the dot.. this may be just a trend for a few days, but i'll find out, and when i make sure it's true i will post the time here, it's over 2 hours i'll tell you that much =) but i think he does despawn after a min or two, i nuked him, then to wipe out my train, i started casting upheaval when tracking reported ' You have lost your target ' before upheaval had landed and i was the only one in the zone that could have killed him due to all of the newbies only corpse that was left was his pet's
oh and he's lvl 23, due to him HTing me for 231 every time he spawned as the HT dmg formula is lvl*10+1 this only works on npcs below 50 as it rises faster at higher levels
Edited, Tue Apr 2 12:39:52 2002