Alright, these explanations make better sense, and I'm taking it all these are also speculation. I'm inclined to add this to Kraco and KraZ's interpretation: If the chakra contained in the body is COMPLETELY used up, then they're dead. There's probably some kind of mechanism involved to prevent that from happening, much like the mechanism in place to prevent someone from using more than a certain percentage of the power that the person's muscles can generate. The amount of chakra that is left when the mechanism activates is well above the amount that would cause a ninja to die. With good stamina, it's possible to squeeze out some amount of chakra despite the preventative measure in place, and so long as the ninja doesn't use too much chakra beyond the cut off, or completely empties himself out, then he ought to survive.

Oh...and NOW I think I recall a display of chakra and stamina being linked in the anime. When Sasuke fought in the preliminaries against a ninja that stole his chakra, he seemed to lose stamina as well. The stamina loss might be due to other effects of the technique, but this is the closest I'm recalling.