We're not the most violent nation on earth (although he makes that claim)...leastwise if you measure by body counts. (Although we are the only nation to drop nuclear weapons on our enemies and our kids do tend to kill one another for the fun of it.)
What's going to get him though isn't the comment per se. The trouble for him is that his rants are rumored to last 20-30 minutes...which is a LOT of class time.
Shrug.