Summary: Kapaku faction questline completion does not pop the "Epilogue" achievement on steam.

Details:

I completed a Quest Victory with the Kapaku faction on a steam account that had neither the "Epilogue" (complete faction quest line) nor "Loremeister" (Quest Victory)  achievements unlocked.  During this game, the Loremeister achievement popped, but the Epilogue achivement did not pop (still locked now).  Possibly a minor bug or oversight in the Inferno expansion.