Here in Tennessee, where this incident happened, you can legally use your weapon to save the life of someone else in danger. Since the guy that went nuts was in the process of stabbing his 8th victim, the gun guy could have just walked up and blown the stabber away, up until the point where the stabber dropped the knives and was no longer a threat. If he had shot the guy, the community around here probably would have erected a statue in his honor. (We're up to 99 murders this year!)
I read last week that people are calling for tougher sentences for knife crimes in England. It seems that young criminals who can't afford guns are going back to using knives.
Of course, this means that the libs are gonna want tougher restrictions on knives in the US. Knife Control! So what if we have to eat steak with our fingers! We must make the world safer for the children!