Gentlemen,
First of all, good points. The decision to draw and shoot a gun at a human should always be a decision to kill, and the jogger was completely justified in making that decision upon being punched in the face.
Here's an article with a little more detail. You guys were spot on; he assumed his assailant was armed, he cleared 360 (covers the other kid while he ran away) and he called the police. The prosecutor was right to let this kid off without punishment.