Well the concept isn't an exploit, but getting the mobs onto you and not the priest doing the quest is. I don't see how the scourge (the zombies you couldn't see) agroe'd onto you, if your just standing there... If you in anyway have any effect on him doing the quest, it will summon a lvl "boss" demond (looks like the demon hunter model) and he'll kill you and anyone within like 50 yards, excepts the priest doing the quest.
The reason you could not see the mobs was because you don't have the Eye of Divinity, a trinket for Priests only that drops out of Major Domo's chest (Molten Core). The scourge spawn randomly during the quest and try to interfere with the priest doing his/her healing & dispelling.
I'm stumped as to how or why you could have stood so close to him while he did the quest without the demon guy spawning. All you did was mana shield? Hhmm, my only guess is that when they spawned from the cave, you were standing somewhere between the Priest, and the scourge spawn point. Either way, you'd be taking lots of damage since they won't despawn until the quest is over (or you kill them). The quest can't be done quickly because you have to heal the waves of peasants that move at their own pace. About 5 waves, each taking about a whole minute to walk by, along with 15 seconds in between each wave. The mobs spawn randomly during the waves and always in between. You would have at least 100 mobs on you ½ way through.
Only 1 way i've seen to make this quest easier (other then lots of buffs from other classes & aura from pallys) is the damn Shaman totems. About the same time I was doing my priest quest, (took me a few tries and a nice chunk of mana pots) I returned to try again to see a troll priest doing the quest with 2 shammies dropping TOTEMS!!! ...I can't even begin to stress my attitude at that time. Totems for healing, totems for mana... NERF SHAMAN, lol.
