Only just found this, what happened was I was doing the quest as normal, throwing parachutes to npc's, I then found this one npc that I could throw the parachute to, but he would lose the parachute buff so you could keep throwing him more, over and over.
NPC Loc: 37.1 - 68.3 (Zul'Drak)
NPC Name: Argent Shieldman
Pic:
I'm not sure if this npc will be there for everyone, as the npc's in this area respawn. But I thought its worth posting =]
Sorry if this doesn't deserve to be in the exploit section, and if the npc wasn't there for you.