Accidental Discharge is nothing to joke about - Video
How many mistakes did this "professional" make?
Amazing. My Dad told me this when he was teaching me to clean his guns. Rule #1 Treat every gun like it was loaded with the safety off. If super cop had learned from my dad he would not have shot himself in the leg in front of a room full of school kids.
He appears to give the pistol a good visual check. He even walks to his left to use the extra light from the overhead projector and show the "empty" gun to the guy standing against the wall. How did he not see a 40 caliber cartridge? Also notice what a calm room full of kids...Like I said, amazing.