This is a game-breaking bug, so I really hope it draws the devs' attention. To put it simply, The Cali/Zephira event loops infinitely with no escape. And since it triggers after the mansion loads, there is nothing you can do to avoid it. Even worse, the menu is inaccessible so Fullscreen users (which the game defaults to) have to either shut the power off or use the Task Manager to force stop it. I tried to edit/delete the cutscene, but the mansion simply wouldn't load after that. The only way I found to avoid it is to sell one of them, so I no longer have both of them. But since they're unique characters there will be no way to get them back. I simply won't play the game until this issue gets fixed.
Edit: Figured I should add my save data in case anyone else has any ideas and/or is struggling to reproduce the bug on their own. And before anyone asks, I did try updating to 0.6.7 and it didn't work.