I was headed from Winterhold to Saarthal to clean-up after clearing it and came upon three Stormcloak soldiers. As I approached the end soldier, a female, stopped and warned me. So I kept my distance while following them. The female got stuck on a large rock while the other two headed away. I waited until the other soldiers were out of sight, drew my bow and downed the female soldier with one shot. After I'd ransacked the dead soldier I noticed one of the other Stromcloakers was headed back! I retreated and watched as he stopped by his fallen comrade, looked at her, then started toward me! I again retreated and offed him with one shot.

I don't remember this type of behavior in the NPCs in OB. Whether the second soldier realized one of his comrades was gone, turned back, inspected the dead one, then headed back toward me or it was coincidence I don't know, but the events that transpired in the confrontation certainly gave that impression!

AI will take notice of dead friendlies and act accordingly. But only as long as you are in sight. As soon as you sneak and are out of view they just go on their merry way like nothing happened.

Yes, friends search for the murderers of their friends. I killed a guy and tried to hide his body in a closet while sneaking. Before I could make it all the way in, his friend found the body, looked down at it and said "I'm going to kill whoever did this!"

He then walked away with his weapon drawn and was fed a nice dose of crimson nirnroot poison to the pocket.

Also, if you feed someone a short term frenzy poison, they will run up and kill the people nearby, then sheath their weapons and walk over the corpses nonchalantly as if they go on slaughter sprees all the time, no biggy.

*Arrow goes though female bandits head, dead*
Male Bandit: Huh what was that?
Male bandit: Must have been my imagination
*Arrow plants itself in male bandits eye, hurt but alive, arrow is visible and remains firmly in his eye*
Male bandit: Who's there?
Male Bandit: I must have been hearing things.
*Males bandit stands there with arrow sticking out of eye, near death with his dead bandit friend laying in front of him, he continue to mutter about a child not being his and how he needs knife boots.*

Yep the AI is pretty intelligent. Although once I did see a bandit kneel over a corpse and swear he'd find out how did this to them. Nice guilt trip.

The worst I'm finding right now is the yeilding system, 90% of the time they fake it and get back up trying to kill you, 5% they yield with 2% hp as your power attacking so they die, the remain 5% they'll yield and live but be like "OH HAI, Whats up man!" , it's just such a dodgy unintelligent system I really wish they hadn't wasted time making it and put the effort elsewhere, I'm tired of checking to see if I commited murder, or giving them a chance they ask for and getting a knife in the face for it, and it's always the ones that you don't want to yield that do, the thief that tried to rob you and will do so again etc. Never the orc you accidently hit with a flame trying to help them take down a giant, then spent the rest of the fight healing them yet the entire camp is after your blood for the 2hp lost even though they made and net gain and only lived cause of you and the sheath system is awful in this unless it's a sword it never works and then it's only if it feels like.