Yesterday two undead used cure critical potions while we were fighting them. The potions healed them substantially.
The first was the ghoul boss on the barrows quest.
The second was the boss on the Jergalite temple quest. His healing from that potion was the final blow that made us have to abandon the quest. :(
Ive had two nightrisers smite themselves with healing in the past, but never actually heal themselves...?
Be sure you're not mistakeing Cure crit for Heal self(undead). They have the same visual effect as far as I know.
There is a difference, and I've noticed the recent use of Heal Self(Undead), particulariy on the jergal quest. I am not sure about the barrows, But I am fairly sure the jergalite one is not a bug.
(Unless you're sure he drank a potion of cure crit, then it sounds like its certainly a bug)
They were definitely using their special harm undead ability (which has the same visual graphic, unfortunately), not using a potion.
If spirits are considered undead .. then we do have a bug. Different quest (Ilythiiri ruins) ... but the boss was using CLW potions
(http://i291.photobucket.com/albums/ll303/WWind_EfU/ilitruinspiret.jpg)
I meant to bug that, my bad!
Hmm, I tested a healing pearl on the Ilythiiri ruins quest boss and it healed him alright. ... And no it was not a misclick while trying to heal myself.