Yeah, it's a glitch. You accept the quest after beating it the first time and the doors closed and nothing happens. All you can do really is quit and reload and don't go back until they fix it...if they ever do.
If this happens to anyone else, don't save, Hit the xbox button, hit Y to escape from the game so you don't save, then you can continue playing. If you do anything that saves the game, you're stuck and you can't get out.
This happened to me, but I had another save that I could still play so it wasn't that big of a deal. If this is your only save, you cannot move on. You're stuck unless they figure out a patch for it.
Heed Capta he knows what he's talking about, just to be clear though this does not affect the main game play through. This seems to happen after you've downloaded the Understone Quest pack which gives you ability to go back to Reavers Mansion and play the
Wheel again, it also opens up the shooting range in the Mercenary Camp... which doesn't work for me either.