This case of LaDue is certainly on odd one. I agree that it isn't clear he actually had the nerve to follow through. But it is clear he is following a script. He calls Eric Harris his hero. He cites all the precedents. Maybe humiliating such perpetrators would not have prevented LaDue, but if it prevented people like Eric Harris, then it would reduce the precedent, and hence probably also the attraction, for people like LaDue.
It's the riot theory the article starts with. If you can deter the people who get the riot started, you can possibly deter the people like LaDue who follow along just because it is now a thing that people do.
I think the way to go is to teach people to think rationally about what others do and why, since if they can marginalize the initial perpetrators, they themselves can neutralize the threat of a violent phenomenon snowballing.
It's the riot theory the article starts with. If you can deter the people who get the riot started, you can possibly deter the people like LaDue who follow along just because it is now a thing that people do.