She pulled the trigger twice, not particularily complicated. Shooting a gun, bigger than she's used to (if she's used to any gun at all). Likely recoil caused her to release, the trigger, then she pulled it again. There's a piece of the ceiling, on display. at my range, from a guy who did exactly the same thing with a casull 454, which is the sole reason you won't find one in my safe right now (they banned anything more powerful than 45 colt or 44 magnum, after "the incident").