During my opponent's turn, my Asawira Lt suffers a second wound and goes unconscious. I privately opt to not use my Farzan's Chain of Command, so the unconscious Asawira is still my Lt. In the States phase at the end of the opponent's turn, I attempt to regenerate the Asawira. If I succeed, I'm not in LoL and Asawira is my Lt. If I fail, I now use Chain of Command so I'm still not in LoL and Farzan is my Lt. Does that work? A) Yes. CoC can be used whenever the Lt enters a null state. Dead is a null state. B) No. The Asawira was already in a null state (unconscious). Entering a different null state when already in one doesn't trigger CoC. I think it's A, but want to check in advance. Since getting opponent agreement at the table isn't really do-able for CoC rules interpretations.
I can see how the spirit of the rule and the text of the rule work against each other here. Adding this to the unsolved list, and I'll be interested to see what people's take on it is.
As far as I'm aware the closest example would be going from Unconscious L1 to Unconscious L2. There you don't "re-enter" Unconscious and can't trigger i.e.NWI or Dogged if taking another Wound while already Unconscious. But here we have this "The player can only activate this Special Skill when the Lieutenant enters Isolated State or any Null State." So question is does this work while transitioning from different Nullstates into each other? Similar to this going from Nullstate to Nullstate (Unconscious->Dead) would be the same principle, you already are in a Null State before you die, so can't trigger conditions that require entering Nullstate. In this case you get a bunch of problems if you don't allow CoC to work after the Regeneration roll. The controlling player has to remember writing down that he choses not to use CoC now and then gambles on his Lt succeeding the roll. If instead CoC just works on Unconscious->Dead you have no micromanagement involved and it's a naturally good option to have a regenerating Lt with CoC that is significantly less niche and less prone to cheating or forgetfulness.