ToddG tells a story of range safety. Frankly, those guys got off easy.
Every time I take my kids to the gun range we go over the safety rules. I also tell my kids that if they see anyone doing something unsafe on the range that they need to speak up. Just because they’re a kid and the offender is an adult, that doesn’t matter. This is a matter of safety, and if a kid sees an adult being unsafe the kid has the right, duty, responsibility, and obligation to speak up and correct them. I also follow it up telling my kids to stand firm in their application of safety rules, and if the person they correct has a problem with a kid telling them what to do, to redirect the person to me or the Range Safety Officer.
Like ToddG said: range safety is everyone’s responsibility.