I've been to many open to the public private ranges and I've seen that and worse. Here's a short list:
Guys at their benches messing with stuff while others are down range.
Guys call the range clear one second and then immediately start walking down.
Guy shoot his ram rod down the range.
Guy pick up something that rolled off the bench towards the targets while the range is hot.
Guys shooting with no hearing protection. (Two shots from my 300 WM and they left)
Tom