This kind of thing happens with a fair degree of frequency at our free public ranges here in Missouri.
In fact, since deer season is coming on, the frequency will increase until opening day as all the once a year hunters take old Betsy to the range for the annual sight in. Many will bring the whole family along with every firearm they have and then the unsafe antics will begin in ernest.
My own shooting will slow down quite a bit now, as it will be crowded at the ranges. Actually, most of the people are quite nice to meet, but one fool can spoil the whole party.
Whenever I see someone at a free range that is behaving foolishly or if I just have bad feelings about someone, I just leave. I am not their daddy and I don't even try to educate them.
The pay ranges I shoot at in Missouri are all state owned and officered and they never allow foolishness with firearms to go unremarked. I like it that way if I'm paying.