I've saved just before that point and reloaded many times to confirm that it is indeed directly related to the dragon shout( I do not know which shout he uses). If I turn off Combat AI and kill the Draugr, I'll be fine, but that's not a viable solution at all. I can assume that this will become a huge problem if I dont fix it so I probably won't play dawnguard until I get it stable.
TL;DR: Draugr using dragonshouts makes game crash.
Does anyone know how to fix this?