He was a local cop attached to DEA. He was not in a DEA capacity when the ND (NOT AD) occurred.
At least he was smart enough to know "I probably won't ever be able to show guns again."
A very similar thing happened here to local cop a couple of years ago. Racked the slide, did not remove the magazine, dropped the slide, pulled the trigger, shot in the leg. In our local case, the fibula was virtually pulverized, the guy was lucky he didn't lose his leg. He was the assistant lead firearms instructor. "This is how accidents happen"