I too was having issues obtaining this quest from Hadoken Swiftrider. I had completed the Zukk'ash Infestation quest in the series and all of the Woodpaw quests including the battle plans but still no Stinglasher quest was offered.  I even opened a trouble ticket with WoW GM.  I was told that everything was working fine on their end and that while he could offer no in-game clues, perhaps I had mised a quest afterall.  So, even though it made no sense, going on earlier post, I completed Deadmire quest in Dustwallow (obtained from Hunter Rise in TB), and voila, I was then able to get the Stinglasher quest.  Hope this helps.