This quest is not in the database:
http://www.wowhead.com/quest=27187
Also after finishing the quest, it wouldn't let me turn it in. The question mark was actually missing with a little brown dot saying the quest is not in the database. So I believe there is an issue if a quest is not in the database it can't be completed "in the field". The brown dot takes precedence over the question mark turn-in button.
That other post seemed to be locked, so I couldn't reply.