I was coming to post this in here as well, but someone beat me to it. My first thought was he forgot or ignored
RULE #1 
ALWAYS keep the gun pointed in a safe direction.
This is the primary rule of gun safety. A safe direction means that the gun is pointed so that even if it were to go off it would not cause injury or damage. The key to this rule is to control where the muzzle or front end of the barrel is pointed at all times. Common sense dictates the safest direction, depending on different circumstances.
My second thought was sympathy for her having watched this and the likelihood of it scarring her for the rest of her life. Apparently he lacked that common sense as a demonstration at the range with a confirmed safe direction to point the gun would have sufficed. The unfortunate part is she may become a new anti-gun activist and he fed the fire to recruit more because of this extremely unfortunate incident.