So I finished the final mission in the expansion (kill the Bile guy).  Yay!  Shower of loot.  I start looting, only to click on the alpha-pariah (who was right in the middle of all of the loot) starting the end-game sequence ... and not letting me loot any more.

Super frustrating, and a terrible way to end what is otherwise a really great game.  There were lots of nice colors of loot, too, that just went poof.