The Federal Court heard that key evidence used to deprive former attorney-general Christian Porter of his lawyer in his defamation case against ABC was improper and odd.
After a tumultuous final two years, Porter retired from federal politics, during which he was accused of an alleged historical rape.
The accusation, which appeared in an ABC story, was against an unnamed cabinet minister, but Mr Porter later revealed he was the minister.
His lawyer Sue Chrysanthou was restrained from acting for him because of a perceived conflict of interest before Porter began his defamation action against the ABC.
They are challenging the earlier Federal Court ruling, which included a costs payment of more than $400,000.
The case was brought up by a meeting between Ms Chrysanthou and Jo Dyer, a friend of the now-dead woman who had alleged that Mr Porter raped her.
Ms Dyer had sought advice about an article in a newspaper that referred to her appearance on ABC's Four Corners program.
Ms Dyer challenged Ms Chrysanthou's right to represent Mr Porter, saying that there was a conflict because knowledge of matters discussed in their consultation could have advantaged Mr Porter in his action against the ABC.
Justice Tom Thawley said that Mr Hooke had drawn Ms Dyer's attention to the article, suggesting that she insinuated her decision to appear on Four Corners was politically motivated and the article might be defamatory.
Mr Hooke was with Ms Dyer when she met Sue Chrysanthou and another lawyer to discuss what to do.
His recollections of what was discussed in that meeting were key to the decision that saw Mr Chrysanthou restrained.
Justice Thawley concluded that there was a risk of misuse of information.
Ms Chrysanthou acted for Ms Dyer in circumstances in which fair-minded members of the public would think that material was disclosed to Ms Chrysanthou, which would be relevant to the proceedings instituted by Mr Porter against the ABC and that Mr Porter might gain an advantage from his barrister possessing such information, he said.
Ms Chrysanthou said she could not remember discussing any confidential material.
The court has redacted all of the confidential details, but they are not known. The court was closed to the public while they were discussed.
Barrister Bret Walker SC, representing Mr Porter, told the court that Ms Dyer's case had hinged on evidence from Mr Hooke, who was simply a witness.
Mr Walker argued that Justice Thawley improperly allowed Mr Hooke's affidavit to be included.
Michael Hodge, who is representing Ms Dyer, told the court that Mr Hooke's evidence was appropriately received.
There was no error in his Honour's acceptance of the affidavit into evidence. Mr Hodge challenged Porter's lawyers over their assertions about the way barristers are assigned cases.
Mr Walker told the court that barristers could not be bagged and they could not turn down a brief. They had to abide by a cab rank rule.
The restraint rule did not mean that barristers were not allowed to represent other people, but in the absence of consent they could not breach confidentiality, according to Hodge.
Lawyers for Ms Chrysanthou told the court that she had never been a finding that she had breached any ethical duties, nor any suggestion that she had not given truthful evidence.
Porter settled the case with the ABC with no damages.
The settlement happened just before a hearing on whether the ABC's defence should remain confidential.
Most of the defence evidence has never been revealed.
A bid to have the suppression lifted was rejected by other media groups, including News Corporation and Nine Newspapers.