Question related to Rafta questline.

(It's been a Hot second since I've posted on Reddit sorry.)

I've been playing look outside, and In my save I killed Nestor's head and and before they could reach their destination. But later on, I enter Eugene's shop and the head got him? I check where I killed the head and the corpse was gone, Nestor's body still 'alive', and the hand Also still alive. I know this isn't a separate save because I don't have another that far into the game period. Is there a trigger for them to be able to get back up or is this just a bug. (If it is I have No clue what I could've done to prompt it) I'm so confused LOL.