It went off when he was removing it from the holster so the safety personnel could affix the security strip. The round struck the concrete floor and ricocheted up into the calf of the guy manning the ticket booth at the entrance.
I was about one hundred feet away, looking at a really nice 1911A1 when the round went off and just about everyone in the entire building (probably 20,000+) hit the floor.
And it's not just after Sandy Hook, we're talking the '90s.
These people like and know guns, and are extremely responsible with them.
In fact, the Indiana State Police are all over these shows.
I never bought a gun there, but I have bought knives.
And they check everyone who leaves.