What, if any training, will assure the public that a gun owner will act in a responsible way in a crisis situation?   *The law is some states exonerates the shooter not because there is a real risk of harm, only that they perceived that there was a chance of harm.    (Very similar to police defense in shooting a child with a plastic gun, or an old man they believe is reaching for a gun.)

But back to the question, it is possible to train a person to make good decision in highly stressful situations?

I trust you for a well informed opinion when it comes to gun ownership and responsibility.