As someone with over 47 years of range experience under their belt, I can tell you that I've seen it all. Hot brass down the back, between the toes or into the cleavage! Miss-feeds, double-feeds, primer-only hand loads that don't go "BANG", hand loads that are double-charged & blow-up Glocks, even a friend that brought 7mm ULTRA-MAG ammo for his 7mm mag rifle & wondered why it didn't fit!
From a bidness standpoint, it's all about running your operation correctly, using computer data to view renting history of a gun renter/customer, having enough RSO's to handle the Newbies & thrill-seekers, and maintaining a tight ship at a commercial range that rents. Places like Gun For Hire get it right. Rentals in a "lock-box", carried by the RSO to the shooting port, and then RSO supervision to make sure you can handle the .50 AE's & .44 Mags before they walk away.
sota's experience is not uncommon. Patience IS a virtue, and can SAVE LIVES! EVERYONE at a private club is their own RSO. Sometimes the Old Farts Club needs a helpful "schmooze" to re-educate them & make them aware of their "faults". Hopefully we'll all grow that old together
Rosey