Moreover, a weapons officer would've been willing to do that kind of work. My point is that McCoy shouldn't have been. "I will not take life, not even to save my own." There's no way that the man who said those words would've so blithely helped modify a weapon to make it better able to kill. It was completely out of character.
I seriously hope that a medical officer aboard a ship does kill someone in order to save 300 of his shipmates and to prevent the assassination of a President and to prevent war, oath or not.