Part of any professional mentality is being able to think things through rapidly and anticipate the results and consequences.
And even professionals make mistakes.
In my opinion, this is precisely why it is CRITICAL to think through things
ahead of time and come up with a basic framework upon which to build real-time strategy.
I'm not talking about trying to come up with a scripted response to every possible situation--that's impossible.
I'm talking about using the advice of experts, personal experience, the study of real-world incidents and a knowledge of the laws of the area where you live to come up with a few basic rules to use as a foundation for your personal policy as regards the use of deadly force.
For example, the person in the news story would not be in the fix he is if he had as a part of his basic response framework the following rule:
Rule: I will not use a gun to solve a problem unless it is immediately required to prevent the serious injury or death of an innocent person.
I happen to live in a state where, under certain very carefully defined circumstances, it is legal to use deadly force to recover stolen property. The problem is, in the heat of the moment, it would be difficult to run through all the points of the law to determine the legality of a particular action. In spite of that complication, you won't be reading about me shooting at a car thief driving off in my vehicle. Because that doesn't fit into the basic framework/foundation of my personal rules for when I will and won't use deadly force.
I've decided that I'm willing to lose a car (or other property) rather than risk killing/injuring an innocent person or risk going to prison because I didn't quite work out the legal details properly in the time I had to respond.
I won't have to "think things through rapidly and anticipate the results and consequences" if I ever find myself watching a thief drive away in my car. I already have a very simple rule that covers that general kind of situation.
Make it EASY for yourself to stay on the right side of the law and common sense.