But, speaking at a press conference yesterday, ANZ chairman John Key said if Hisco was there he would have taken some of the blame.
But, he said, the issue was created by a "junior staffer".
Speaking to media this morning, Robertson rubbished this response.
To blame the error on a junior staff member was not an acceptable response, he said
"It is the responsibility of the board and I'm sure Mr Key knows that."
Robertson was highly critical of the Reserve Bank censure of ANZ.
"I take very seriously the censure that was given to the ANZ for failing to keep to their capital models.
He said this comes down to the relationship of trust between the Reserve Bank and ANZ.
"I am extremely disappointed that the ANZ did not meet the arrangement that they had."
Asked about Hisco's departure, Robertson said that was an issue for ANZ's board and its shareholders.
Yesterday, ANZ said Hisco would be leaving the bank's top job after it was revealed some of his personal expenses, including chauffeur-driven cars and wine storage costs, were being paid with company money.
Robertson this morning said Hisco's departure would not sit right with the bank's owners.
"I'm sure there will be ANZ shareholders and staff members who are very disappointed in what they have seen here but I don't think that would necessarily mean a systemic issue."
He said there were still some questions ANZ needed to answer about the saga, particularly around the disclosure of when this occurred and making sure the ANZ did fulfil their requirements.
"I know the Reserve Bank is still talking to them about that incident."
