I actually had this bug, so after killing all of the Zhentarium hideout because they wanted to talk to me while beating on Rugan but as soon as I went to talk to the woman they all went hostile. I returned to the hideout later to unlock the elevator and picked up bits and pieces (as everyone there was dead) I found anywhere I went after that including camp was hostile and claimed I was a thief/tresspasser etc. Luckily I loaded before going back to the hideout and continued the game and ignored the loot and elevator. Replicated it 3 times to make sure it was returning to the empty hideout and interacting with the loot/elevator.
