Have to say, I very much disagree with Bane on this.
The idea is, basically, once you make a decision you no longer question it.
However, at least in CA, and for my own ability to go on after, when I pull the trigger someone must be in mortal danger.
The idea that blood must be drawn once the gun is drawn may work for samurai and cops, but us normal folk are held to a higher standard. You must always question your situation...
All IMHO of course.