A very detailed, and interactive, report about that event  has now been published by Stuff.
The article is sourced from multiple in-depth interviews with people directly involved. It covers both the accident and the rescue operation, and its narrative flows from the beginnings of decisions which combined to cause things to unravel into a disastrous situation, through the attempts to plan and deploy rescuers, and eventually to the eventual musings and hindsight of what people wished had happened differently.
The article isn’t not short, but it’s worth setting aside the time to read for the narrative of how things can go wrong, and insight into the presumptions which are sometimes made about rescue services.
This event stood out to me. Accidents happen sometimes, even to those involved in the NZ Alpine Club. This accident was considerably more significant that most in how it was caused and what was at stake. Instead of being an accident due to an individual error, it was caused by a long stream of decisions, assumptions and lack of communication. The better part of a group found themselves at serious risk. Of that group, two eventually died. Another two nearly died. The fate of more hung in the balance for a time. At worst it wouldn’t have taken much for it to have become another nurses tragedy .
I’m not intending to be critical of the NZAC generally. As far as I can tell, this event seems an exception to the rule for the NZAC. The NZAC also immediately, and proactively, took very public steps to investigate what happened—much more rapidly than the coroner—and learn from it. I’m also not intending to be critical of the people involved. I’ve experienced how sometimes group events can get out of control, and it’s not always easy to see coming.
It’s easy to point fingers, sometimes for good reason, but it’s not always useful and not always accurate. For me this highlights the importance of individual group members to take a personal stake in what’s happening and how its happening, instead of just expecting to follow a leader. Everyone needs to trust each other. Everyone needs to be clear about what others’ expectations of them are. If those expectations don’t match up, people need to very clearly tell each other.