Antoinette Lattouf was recruited to host the Mornings show on ABC Radio Sydney for five days - Monday to Friday - in December 2023.
However, the 41-year-old was let go following three days on air after sharing an Instagram post by Human Rights Watch saying Israel used starvation as a "weapon of war" in Gaza.
As an unlawful dismissal case continued in the Federal Court on Wednesday, Lattouf's barrister Oshie Fagir argued the ABC's claims her Human Rights Watch post breached impartiality guidelines had no foundation in any policy, procedure or legislation.
"What we propose to submit is that the rule as it has been articulated is utterly incoherent," he told Justice Darryl Rangiah.
It was "plain as day" there was no such obligation because ABC broadcasters often made public statements without being taken off air or being subject to other sanctions, Mr Fagir argued.
While the ABC's editorial policies comment on impartiality in terms of the gathering and presentation of news, they do not cover personal social media posts, various of the broadcaster's witnesses have agreed.
The submission came as he cross-examined ABC audio director Ben Latimer, who said Lattouf expressed a partisan view that was sympathetic to Palestinians in the Gaza conflict when she shared the post.
Former ABC chair Ita Buttrose, outgoing managing director David Anderson and then-content chief Chris Oliver-Taylor all previously raised concerns in court about Lattouf appearing impartial because of her prior statements about the conflict.
Mr Latimer said he had been given a direction by Mr Oliver-Taylor, his superior, to order Lattouf not to post anything on social media about the war.
Whether this direction was given or not is a critical issue in the case as the ABC says Lattouf was taken off air because she ignored orders not to post anything relating to the Israel-Gaza conflict.
She says she was never given a direction, but rather was advised by her supervisor Elizabeth Green to keep a low profile on social media.
Lattouf claims she was fired because of her political opinion and race after the ABC bowed to pressure from pro-Israeli lobbyists co-ordinating a campaign of complaints.
Under a lengthy grilling, Mr Latimer remained steadfast the direction had been passed on to her through former head of capital city networks Steve Ahern.
"My words were very clear," Mr Latimer said.
Then ABC acting editorial director Simon Melkman said on December 20, there was consensus Lattouf had breached the direction by posting a "controversial" allegation that was denied by Israel.
"Because Israel denied it, Ms Lattouf couldn't post it?" Mr Fagir asked.
"That is absolutely not what I'm saying," Mr Melkman replied.
Ms Green also testified on Wednesday, saying she learned from Mr Ahern during a meeting on December 20 that the casual host would not be required for her final two shifts because of the post.
"You also expressed the view that you did not see anything wrong with Ms Lattouf's post?" asked the journalist's barrister Philip Boncardo.
"I did say that," Ms Green replied.
After Lattouf was let go, Ms Green said she had a private conversation with the crying journalist in an ABC boardroom.
She told Lattouf she tried hard to stop her being dismissed but believed the call had been made from "higher up".
"I said there was pressure for her to be removed from the Monday," Ms Green told the court.
Ms Green said she heard from Mr Ahern that the decision had been made from Mr Anderson's office.
Mr Anderson earlier told the court he thought the trial outcome would determine whether the ABC's integrity was affected.
Closing submissions will be made over two days from February 27.