I am sorely disillusioned! I read in one or another thread around here that pickpocketing a Briarheart's Briarheart would kill him instantly. So...

There I am in a DiD competition yet, I 'm doing the "Find Hjalti's Sword (or whatever)" quest, and I pick the Briarheart's pocket. I took his Briarheart, all his gold, gems, and his snack lunch leaving whim wiht NOTHING in his inventory, and he turned around and nearly killed me before I could get out the danged door. I've gone back in 3 times, used every healing potion I had, and one level up, and I just plain CAN'T KILL this guy even though he has no heart.

The UESP says Briarhearts die instantly if you steal their heart by pickpocket, so... does anybody have any idea what is happening that keeps this energizer bunny zipping along?

did he detect you taking it?

Nope, He turned and started walking away, so I stabbed him with a poisoned dagger, and that's when he went all Rambo....

I don't know what the issue is, because I've seen the script setup and that is indeed what is supposed to happen. Did a mod break it perhaps?

Well, this a competition playthrough, and I really don't have much in running in the way of mods. What I do have running is mostly eye candy type stuff, and I can't think of a one that would change a briarheart script.

After my last post, I reloaded the game, and went back in where this guy is. He was still walking around, only now he's invisible except for his headdress, his gloves, and his boots. I've decided I can't beat him, so I stole the items I needed to finish my quest and left him in peace. I'd love to know what happened though. Oh, and I double-checked my inventory, and the stolen Briarheart is in it. I know I didn't have one when I first went in, so he couldn't have caught me picking his pocket, eh?

I'm pretty sure something is overriding the briarheart script in your setup.

As for the non visible body parts, I recall Cloaks of Skyrim having problems with USKP and causing hilarities like this. If you use it, you'll want to take a look at the http://www.nexusmods.com/skyrim/mods/56922/?.