I'm pretty sure he is kidding. If we can't joke about horrible things, then we are doomed to be miserable creatures forever because the world is a pretty horrible place -- hence Columbine. Who is anyone to say how a person should react to a situation or with what level of reverence it should be treated? The Spanish Inquisition was a horror that I am certain you have never come close to witnessing, yet Monty Python makes light of it. Are you saying the S.I. Python skit wasn't funny? If that isn't what you are saying, then why is it okay to make light of torture, but not Columbine? Is it because Columbine involved kids or simply because you can actually remember when it happened/were alive? Either way, a joke is a joke. It's not shitting on a victim or victims. It doesn't take away from the severity of the situation. I made a joke about it and think it was a very horrible situation. One does not erase the other. A sense of humor is a funny thing. 
