What's more, he never revealed to whom he spoke, and he rarely took written statements. Mahon's inquiry, on the other hand, took place under full public scrutiny in the clear, open light of day.
There has been some comparison this week between Robert Muldoon and John Key. This originated in one of Bryan Gould's pieces in which he once again reminds us of how important he was in British politics. Gould compares Key with Muldoon. It is nonsense. Key is no Muldoon.
Muldoon was an intimidating monster. The more I studied this whole Erebus matter, the more I realised how right we were to detest Muldoon. There was no way Muldoon was going to let the truth prevail in determining the cause of the accident.
For Key, decency and truth would prevail. I have no doubt. All you need to know about the two men is that Key comes from a state house in Christchurch and Muldoon fell out of a space ship one dark and evil night.
It went like this. If the pilots were to blame, then the airline or the Government would owe the families of the passengers US$42,000 dollars. The families of the crew were covered by ACC. New Zealand passengers were not covered by ACC because the aircraft was more than 480km offshore.
If the airline was found to be culpable, then claims for damages would be unlimited. Already, months after Mahon's report was published, Air New Zealand was facing claims in excess of $80 million.
What's more, Air New Zealand and the Antarctic flights were regulated by the Gilbert and Sullivan Civil Aviation Division. As a department.
Civil Aviation was as anxious as everyone else to cover its own backside. My book shows how close Civil Aviation came to being sued for tens of millions for negligence.
Civil Aviation rubber-stamped the airline's request very early on that the department waive its requirement that no pilot should command a DC-10 to Antarctica unless he had flown there under supervision at least once before.
The RNZAF, the RAAF, the US Air Force and the US Navy all required their pilots to have flown to Antarctica at least three times under supervision before commanding a flight themselves, so tricky are the flying conditions there.
In end, the accident was caused by the change in the destination waypoint co-ordinates hours before the flight without the pilots being told. There was nothing whatsoever on the flight plan to let them know. What's important is there was nothing to cause Jim Collins to think he was flying anywhere other than straight down the middle of McMurdo Sound.
Mahon saw the importance of the co-ordinate change straight away. Chippindale actually said that the co-ordinate change did not mislead the pilot. Chippindale's findings were absurd.
What's more, Chippindale said, the flight engineers were trying to get the pilot to straighten up and fly right. This was nonsense, a cruel lie. It didn't happen.
Collins plotted his route the night before the flight on a couple of maps. He showed his two older girls where he was going. He could only have plotted the flight if he had taken home one of the digital flight plans handed out at his briefing. After the accident, his head office knew one of them was missing. That flight plan took the DC-10 down the middle of McMurdo Sound, over the safety of flat sea ice.
I mean, ask yourself. Why would you programme a jet airliner full of people over an active volcano permanently belching steam?
Chippindale said Collins didn't have the maps the girls described. He effectively called the girls liars for saying Collins was working on his maps. In his rambling denunciation of Mahon released in early 1982, he effectively claimed they had perjured themselves.
It was a frightful business. The pilots got the blame for one reason only. They were dead and couldn't protest. And if it broke the hearts of the families, so be it. There was an airline to look after. And backsides were running for cover.
The Collins girls suffered not only the death of their beloved father. They had to watch while he got the blame.
In the end, make no mistake, the Privy Council backed Mahon entirely on causation. They were emphatic. The judge had completely "displaced" the chief inspector on causation. Mahon was right, their Lordships said. Collins had been fatally deceived.
I hope Daughters of Erebus puts a few things right at last.