This has the hallmarks of a cultural problem which I sincerely hope has been addressed.
Exactly. The badly managed approach is a CRM issue. Look at all the bits that contributed to it and fix them. Proper MCC and SOP adherence included.
Saying the crew were negligent doesn't‘ really do much to stop the next badly managed approach. I bet the crew concerned would give their eye teeth to go back and do it differently. And would never do it like that again. But without an analysis of why they did it that way, why the monitoring broke down, why the MCC/CRM was inadequate, the same and other needless events await to befall other crews. The crew know they buggered up. Understanding why is the lesson for all of us.
I cannot tell you how many VS mode descents with the airspeed being flown with the collective I‘ve witnessed. It was certainly the preferred method at one company. This crew were the saps who demonstrated why it isn’t a smart way to fly a helicopter.