The influential O'Neill has also advised Australia to go it alone in a bid to host the 2027 World Cup, rather than farm out some pool matches to New Zealand.
Current Aussie chairman Hamish McLennan has been diplomatic over Hansen's belligerent words, but that was never O'Neill's style.
O'Neill said the NZRU had stuffed it up in 2003, and a report by former New Zealand Chief Justice Sir Thomas Eichelbaum proved it.
"I'll paraphrase the conclusions; the NZRU shot themselves in the foot," O'Neill told the Sydney Morning Herald.
"Rugby World Cup and the International Rugby Board had particular conditions about clean stadia and you either had to comply or lose the hosting rights.
"Yes, the terms and conditions for hosting may well have been onerous…but in our language, like it or lump it. New Zealand Rugby – through arrogance and hubris – thought they could force the IRB and World Rugby to change the rules. They didn't.
"Judge Eichelbaum's words about me were that I did no more than act in the best interests of Australian rugby.
"New Zealand Rugby at the time got rid of the board who stuffed it up. They got rid of the CEO [David Rutherford], [chief operating officer] Steve Tew stayed on and later in 2007 became CEO. Steve was No. 2 to David Rutherford and he remains one of Steve Hansen's best friends.
"Steve Hansen can make as many comments about rugby as he wants…in this case he was not in the vicinity and it's a part of the game he wouldn't know anything about."
O'Neill said Hansen's claim that 2003 showed how Australia let New Zealand down "didn't stack up".
New Zealand was officially the 2003 sub-host and the agreement became null and void because the NZRU crossed out clauses it didn't like.
O'Neill was amazed that New Zealanders were still apparently upset by the 2003 controversy.
"It's absolutely absurd. Move on," he said.
"Brinkmanship only gets you so far.
"It would be foolish to say Steve Tew and I had a close relationship. It was a particularly sensitive matter for Steve, not for me, and it is what it is. You can't re-write history to serve your own purpose."
O'Neill said the success of the 2003 World Cup relied heavily on all the games being played in Australia, and they should repeat that formula for 2027.
"It's ours to lose," he said.
"I wish Hamish every success in the world. I'm available for a conversation at any time."
Meanwhile McLennan told the Australian: "This is a moment in time and we will rebuild Australian rugby and at some stage in the future we will repay the favour to New Zealand."
The implication is that if New Zealand was more accommodating of Australian teams in a post-Super Rugby competition, it would allow the All Blacks to host its pool round in the 2027 World Cup.