Your scenario is just as contrived as the first one. It assumes a complete and accurate knowledge of the situation as well as a perfect ability to execute on your decision to harm the shooter.

If your only means for investigating the nature of human relationships is via intellectual contrivances then you will always produce results which reaffirm your preexisting beliefs.

The first point to understand is that violence is a dicey business and never produces as tidy of outcomes as the intellectual justification for it expects. The second point to understand is that the pursuit of morality via intellectualization is counter-productive at best.