The inquiry uncovered banking practices where customers were charged about A$1 billion ($1.05b) in fees for no service, dead customers were charged fees, and people were given poor financial advice or bullied into buying inappropriate insurance and high-interest loans.
In the final report Commissioner Hayne singled out NAB for the harshest criticism and said its response stood apart from the other three major banks.
"Having heard from both the CEO, Thorburn, and the chair, Henry, I am not as confident as I would wish to be that the lessons of the past have been learned," his report said.
"More particularly, I was not persuaded that NAB is willing to accept the necessary responsibility for deciding, for itself, what is the right thing to do, and then having its staff act accordingly."
During the inquiry Henry, who has been NAB's chairman since 2015 and is also a former board member of the Reserve Bank of Australia, was slammed for his responses to senior counsel assisting Rowena Orr QC.
One exchange was particularly revealing and happened after Orr asked Henry about the 11-month delay in NAB executives telling regulator ASIC it had charged customers A$34.6 million for services they hadn't received.
Orr: Do you accept that the board should have stepped in earlier?
Henry: (long pause) … I wish we had, let me put it that way … I still don't know …
Orr: I'd like you to answer my question Henry. Do you accept that the board should have stepped in earlier?
Henry: I've answered the question how I could answer the question.
Orr: I'm sorry, is it a yes or a no Henry?
Henry: I've answered the question the way I choose to answer the question.
Orr: Well, I'd like you to answer my question. Do you accept that the board should have stepped in earlier?
Henry: I wish we had.
Orr: I'm going to take that as a yes, Henry
Henry: Well, you take it as a yes. All right?
When asked about the huge bonuses paid to bank executives, Henry began talking about the state of capitalism.
"The capitalist model is that businesses have no responsibility other than to maximise profits for shareholders," he said.
"A lot of people who have participated in this debate over the past 12 months have said that's all that you should hold boards accountable for, is that they are focused on the maximisation of profits for shareholders."
Twitter users were not the only ones who thought Henry's responses were unacceptable.
"I thought it telling that Henry seemed unwilling to accept any criticism of how the board had dealt with some issues," Commissioner Hayne said in his report.
In contrast to the Commonwealth Bank of Australia, which has given an enforceable undertaking it will act on each of the report's 76 recommendations and an independent reviewer will report its progress to APRA, the NAB has instead announced a process of self-assessment on 26 actions.
In a statement released this morning Henry addressed the criticisms, saying: "The royal commission has challenged NAB and we have welcomed that. We led the sector in calling for the royal commission to be held.
"In his final report, Commissioner Hayne said I seemed unwilling to accept criticism of how the board had dealt with some of the issues raised by the commission. I am disappointed that the commissioner formed this view. I know that it is not so.
"The board and I have reflected deeply on those and other issues and, as I have said previously, we take them very seriously.
"We have said we are not prepared to accept good intentions where urgency, consistency and discipline is required. The board has led a deep examination of our culture, governance and accountability. We are the only bank to publicly release our assessment, which clearly outlines 26 areas we are focusing on to be a better bank.
"It is our highest priority for everyone at NAB to put customers first. At NAB we are determined to change and accept that we will ultimately be measured by the actions we take."
Thorburn is also standing firm against the criticism and has cancelled two months' leave, saying he is "more determined than ever" to lead the bank and its response to the inquiry.
He also hit back at criticism about his decision to go on holidays as the bank navigated fallout from the commission as well as restructuring changes, saying he had raised his long service leave with the board a year ago.
"I think it's a bit unfair to think that a CEO can't take leave for their own physical and mental health when they've laid out a plan and they've got an army of very good leaders who are carrying out that strategy."
In his report, the commissioner said he thought it was telling Thorburn treated the fees-for-no-service issue as being caused by carelessness combined with system deficiencies, even though the total amount NAB and its superannuation trustee NULIS will have to repay is likely to be more than A$100m.
Commissioner Hayne also pointed out bankers were being urged to sell at least five mortgages each before Christmas during the week the two leaders were due to give evidence at the commission.
"Overall, my fear — that there may be a wide gap between the public face NAB seeks to show and what it does in practice — remains," the report said.
