Prospector,
I suggest Ampan has understood me. I am not drawing parallels between actual cause or type etc. but more that it is possible to exonerate people who actually have their hands on the tiller at the time of the incident, where they quite reasonably think one set of circumstances exist when, in fact, another does; the real fault then lies with what prevented them from being in possession of the full set of actual facts.
This is important because if, for instance, blame for the O'Hare DC10 had been laid with the pilots' mistaken reduction of power - "it was recoverable, if they had not reduced speed below 159KIAS, so the fact that they did so, makes them to blame" - then a host of other issues would not have been looked at - AA's maintenance, the fallibility of the DC10 engine attachment, FAA oversight, etc.
So to with Erebus - whilst it is undeniable that TE901's crew flew below 16000', to then say they are fully to blame would have meant other human and organisational factors would not have been fixed.
This is a learning process. Aviation learnt many things from TE901 and that is the legacy of Collins, Cassin and all the others who perished that day.