wouldn't that be considered good AI then? They noticed a intruder that is not part of their outfit and they wont stop looking for you until they kill you (if i am correct this is after a nuclear apocalypse, so resources are scarce, everything and anything should/could be gathered), I get its frustrating but I would think that would be the best part of the game. Make sure you dont get seen and if you do prepare for a battle. I dislike AI that forgets an intruder is around and stop looking after like 30s-1min.