In the case where the stock safety would not have been disengaged, we spent a lot of time on it. I had strain guages mounted on the safety buttons, triggers and trigger guards. Basically, due to the dimensions of the users hand (fat stubby fingers), he could not disengage the safety and fire the tirgger with ONE hand position. It had to be shifted.
In none of the cases was horseplay, drugs or alcohol indicated.
Good Shooting, MarkCO
.40 S&W Club #1, 1911 Club #1067
NRA Life Member and Certified Instructor