Antoinette Lattouf was hired as a casual presenter for the Mornings show on ABC Radio Sydney over five days in December 2023.
But the 41-year-old was dismissed after three days on air after sharing a Human Rights Watch post on Instagram saying Israel had used starvation as a "weapon of war" in Gaza.
Outgoing ABC boss David Anderson stepped back into the witness box during an unfair dismissal hearing in the Federal Court on Thursday.
The managing director said, under questioning by Lattouf's barrister Oshie Fagir, that the freelance journalist should not have been hired for live talkback radio.
"I believe that was a mistake, yes," he said.
He told the court he was concerned someone could have called up Lattouf to discuss the Gaza conflict while she was on air and that it may be difficult to comply with the public broadcaster's obligations of impartiality.
After the ABC received a co-ordinated campaign of complaints directed through a WhatsApp group, Mr Anderson ordered chief content officer Chris Oliver-Taylor to investigate the 41-year-old.
Lattouf alleges this WhatsApp group was titled Lawyers for Israel.
"The thrust of each and everyone of these (complaint) emails were that Ms Lattouf's criticisms of Israel were anti-Semitic," Mr Fagir asked.
"Yes," Mr Anderson replied.
While Mr Oliver-Taylor's team found Lattouf had not breached any of the ABC's policies, Mr Anderson personally googled her and browsed her Instagram account.
He forwarded some screenshots onto Mr Oliver-Taylor, telling him the ABC had an "Antoinette issue" as her social media feeds contained "anti-Semitic hatred".
On Thursday, he told the court he abhorred racial hatred of any kind
However, he denied being personally offended by the things written on Lattouf's socials, instead saying he was "challenged" by the comments.
Measures were taken to prevent her discussing the Israel-Gaza conflict on air or post about the topic online, he told the court.
After her third shift, she was let go for allegedly breaching this direction by sharing the Human Rights Watch post.
She denies being given any such order.
The broadcaster's boss admitted her dismissal was "abnormal" because she had not been given a chance to defend her actions.
Mr Anderson had always wanted Lattouf out of the organisation, Mr Fagir suggested.
'You were not about to interrogate any decision to take her off air because that is exactly what you wanted?" he asked.
"That is not correct," Mr Anderson said.
The managing director was also grilled about an email he had sent to then ABC chair Ita Buttrose which said Lattouf would make a "managed exit" even after the claimed measures were put in place to reduce risk.
In this email, he wrote the broadcaster had been placed in an untenable, unacceptable position by hiring the Gaza advocate.
Mr Anderson denied the phrase "managed exit" referred to Lattouf leaving the ABC but instead meant managing any risk during her time there.
Mr Fagir called this reasoning "nonsense," a claim that was swiftly denied.
The hearing continues.