It seems that currently the quest can be taken by multiple parties at a time, leaving all but the first one very little to deal with if they don't combine forces.

There are some issues with this quest.

(1) Since it's low level and can be soloed, people take the quest and then log out or give up.

(2) This in turn breaks the quest, requiring it to be reset. If they give up, the encounters corresponding to the spawned monsters don't correctly reset (which is why sometimes a group will take it and find no monsters).

(3) Once reset, there appear to be times when it behaves oddly -- letting multiple groups take the quest, for instance.

These are known issues, I really hope we can get them fixed soon.