Ok, final PS:
After making the change I mentioned and triggering the "sacrifice" reveal I've tried feeding a couple of my slaves to the crystal. Each time their text box displays "....", no choices are presented, and I have to restart the game. I don't see any messages in the console, and I have no idea on the cause in code.
If I were to take a wild guess... I'm wondering if what I believe are recursive calls in `crystalconsequences` are causing the character to be killed then trying to set up more dialog with the character when it goes back up the tree? Purely a guess, and I'm afraid I don't have the time to experiment with it right now.