The scene that plays out when you throw the blade lasts for over a minute. The blade will disappear/reappear and then be lootable.
If that didn’t happen, you should be able to abandon the quest and return to Halduron Brightwing to pick the quest up again.
Even if you needed to submit a ticket, no, should not wait there for a Game Master. You being there, or even in-game, wouldn’t make any difference in what our staff would be able to do.
In this case though, just abandon and retake the quest.