Wrong. AI can torture creatures. In fact, by playing the second level of the Ancient Keeper campaign, the first time I played it with the original DK game, I have no idea what happened, but I got some of my Vampires to be tortured in the enemy Torture Chamber. I don't know if it's because of the Teleport spell or about which owner is the room (like if the Vampires are in the room while an enemy Imp claim the room), but I got my Vampires to give informations to the AI Keeper, then they got converted to the enemy side.