This appears to just be a bug with the door animation. If you don't complete the quest, the intent seems to be that the Gilded Lily just continues to operate. The Gilded Lily quest is impossible to complete (along with Mismanaged Funds) after Return to Stineford - just not marked as failed, which could be changed. Thanks for the reports, and I will pass them along to SL.
You'll still need to restore and decide what to do with the succubus before completing the section.