sap exploit on the manaforge q's

I was out farming quests in netherstorm on my rogue to get some cash for epic flying mount. I am Aldor so I got a quest from the Aldor quest giver in area 52 called "shut down Manaforge B'NAAR". I already knew what to do on the quest since I had done it on my warlock. So I just went there and got the key and then started the quest event. When the mobs started spawning I saped one mob and then I noticed that when I saped another mob the last saped just stood there and did nothing. So I continued to just sap and after a while the mobs just despawned and I cleared the q without doing anything but saping.

This is confirmed, I have done it on every single one of the quest followups rly gr8 for the lazy boy who doesn't want to kill mobs without getting any loot.
http://www.multiplayerstrategies.com/ms/index.cfm?page=topic&forumid=63&topicid=38088&tempview=0&rid=0.5904002160249844

So I continued to just sap and after a while the mobs just despawned and I cleared the q without doing anything but saping.