I have the answer! Evoking one of my favorite movies, the Princess Bride, I can tell you for certain that

Quote Originally Posted by Miracle Max
There's a big difference between mostly dead and all dead. Mostly dead is slightly alive. With all dead, well, with all dead there's usually only one thing you can do. ... Go through his clothes and look for loose change.
0 HP= mostly dead. Tallah=all dead. Mystery solved.