I would have thought that Bethesda would have fixed the AI in Skyrim. Nope:
1. So I'm exploring some Draugr ruins. Some oil lights up after I try to burn a Draugr. Lydia decides to charge in and attack. Upon killing this Draugr, she repeatedly tells me to stop attacking her, and makes no attempt to exit the fire.
2. Upon killing a Master Vampire for a quest in Morthal (in which you help some ghost girl and kill some vampires), I begin to feel pretty epic with myself. I head back up to the entrance of the cave, where this little ghost girl awaits. Just as I'm about to say "I have avenged you and your mother", the blurts out "I think mother's calling me. Bye!".
Behold; the art of killing the moment.
Oh, and later I got drunk and sold a goat to a giant.