That is one thing I did not understand well... why no attempt to leap on the shooter. Someone might have yet gotten shot but then that could have quickly been the end of it as the shooter could not shoot everywhere. This is a good example of sacrifice for good, which Christian faith is supposed to exemplify to a T.
I am Catholic. Aquinas made it quite clear that pacifism in the face of the imminent death of one of Gods human creations is not only wrong but sinful. Having said that civilians are not trained to attack the ambusher. They are taught to cower in place.