...My feeling about self defense is not to second guess what happened. He was there and he was safe. He was paying attention and knew what to do...who are we, who weren't there to say that we know better than him?
A major part of budo is reflection on things that happened, consideration of what we might have done better to avoid the situation from the beginning, or recognition that what we actually did was not the best we could have done. It's the same as practice.