This is not a forensic issue: Any intelligent person who who can be bothered spending a few hours examining the evidence will, if venturing an honest opinioin, ascibe a degree of fault to the crew and, in particular, to the captain.
This is nothing more than applied politics. NZALPA know that they got very very lucky with Mahon, so they continue to try to keep his conclusions embedded in stone – and it has worked, for 34 years.
The fact is that most NZers, if asked about the Eerebus disaster, would trot out a version of Mahon’s report. So congratulations, NZALPA. Well done.