That statement, whilst correct, is not the whole story.
I think we are probably in agreement here when I say the 'whole story' in relation to the Erebus incident was:
1. Pilot error.
2. Systems failures which by themselves should not have been causative.
Getting point 2 into context is where so many - including Mahon, who should have known better - have come unstuck.
Here's an analogy which I thought of. Aircraft A has some substandard work on an engine done. This causes a reduction in power, and Aircraft A has to fly slower than it otherwise would. An ATC error causes Aircraft A to collide with aircraft B. This would not have occurred had Aircraft A been flying at the normal speed.
The engineer who worked on Aircraft A made an error. Had this error not occurred, the accident would not have occurred. But did this error cause the accident, and should the engineer be responsible for it? In no way, shape or form.
And the same goes for the briefing/NAV track change/"whiteout" etc. in relation to the Erebus incident.