The "You are knocked unconscious by the force of XXXXXXX's blow!" line is just misplaced. D has said in the past that sometimes the placement of various lines aren't in the right order. Thats no bug. The fact he couldn't move/speak after he was dead likely is a bug however.
As far as...
Code:
You feel weaker.
You feel yourself slow down.
Your rage ebbs.
Your disguise wears off.
You no longer see in the dark.
You no longer feel stealthy.
I'm pretty sure there is no bug here because there is nothing odd about it. Unless of course he wasn't G-strenght, hasted, frenzied, disguised, detecting invis, and/or sneaking.
sleeper