The relevant issue is whether the captain should be "exonerated". No blame at all. So of course there were multiple causes, and of course others in the airline were also to blame, but no-one could reasonably suggest that the captain displayed faultless airmanship.
If I had to select one particular AirNZ employee who has to shoulder most of the blame, it would be Captain Collins. That might not suit his surviving family members, but their feelings are completely irrelevant. Every dead careless pilot had a family.
Thats it in a nutshell right there.