Everyone wants to spread and diffuse blame for some reason.
All people die, every one of them. That's an inescapable truth.
Risk based activities are risky !
I climb, I shoot, I skydive, I scuba dive, I do a bunch more. In none of those activities do I have a police badge. If I feel inclined I can give my opinion when I see something unsafe, but it's an unsolicited opinion and will almost for sure be received as such. In the end, if it's not endangering my team it's not my business how people want to live or die.
That may sound harsh but it's reality. In almost ever case where you give advice on unsafe practices you wil be ignored, and nothing bad will happen as the incident rate of bad things is low. Your advice will be "proven" to be false and unwarranted.
I can advise people to get training. I can choose and vett who I go on big glaciers with etc. but it's not my job to police the mountain. I know a kid who is a self trained climber, he almost crippled himself this year, is recovered and is now self training in ice climbing. He is going to permanently cripple or kill himself. There is nothing I can do about that. Nothing. But anyone with any expereince and training knows his death is an inapescapable logical conclusion to his choices.
If I see someone making an obvious mistake I'll say something, especially if I know they know better and are unaware of the mistake they are making. Otherwise I don't pay any attention to other teams unless they are impacting my safety. It's not my job and it takes away from what is my job, ensuring me and my team are doing the right things.
Im sure that my opinion will be received negatively.
Life is risky, diving is risky, cave diving is riskier, deep diving is risky, deep diving on air is riskier. Deep diving on air in a cave without training in deep diving or cave diving with new and untested equipment is at the far, far edge of risk. People are going to die.