There's no "Ooops" or apology sufficient for an AD or ND. I've had two (fortunately with no real ill effects) in sixty years of shooting and if that ain't gonna teach you good, nothing will. I can testify that there's no louder sound than when you get a bang instead of a click.
As far as gun handling is concerned, it's only relatively recently that there's been a lot of "consciousness-raising" with respect to firearms safety rules. It seems to me that up until about ~twenty-ish years ago, after initial new-shooter instructions, the rules were almost implicit, rather than stated frequently. Just seems that way. I wonder if this coincides with Cooper's distillation down to "The Four Rules."
By the way, a couple of NRA Director elections ago, Selleck was the single biggest vote-getter.
Shouting out danger is not necessarily "anger" or "losing your temper," by the way.
A stern lecture with elevated voice isn't, either.
However, with Selleck's imposing physical presentation and deep voice, I have no doubt that a couple of wimpusses were "surprised" and had the backs of their hands touching their collarbones, with their mouths forming a little "O,"
ETA: You only have until 10 Apr to get your NRA Ballot in to the vote-counting outfit. Not postmarked 10 Apr, but received by them.
Terry, 230RN