Was it big boy rules?
So, one of those guys that posts training videos on the internet that gun blogs link to and point out the suck and fail? Yeah, he went and got himself shot:
Unknown to him [Sonny Puzikas], one of his instructors was still inside when he opened fire with a 9 mm semi-automatic pistol, striking unaware instructor in the hand and twice in the abdomen.
Be sure of your target.