Jones, 85, is standing trial in Sydney after pleading not guilty to 22 counts of indecent assault and sexual touching without consent against six men between 2003 and 2020.
One complainant is a former radio staffer who claimed he was repeatedly non-consensually kissed and groped by the longtime breakfast shock jock over five months.
He confided years later in Hadley, who was Jones's rival and stablemate at leading Sydney radio station 2GB.
Hadley returned to the witness box on Wednesday, when Jones's barrister Gabrielle Bashir SC referred to text messages between Hadley and the staffer.
She asked if Hadley wrote the words "Jones outed as a f****t" in a text with the radio staffer around the time he disclosed the alleged indecent assaults.
"It appears to be the case, yes," the long-time 2GB mornings host replied.
He accepted he wrote the "strong" word in the text but maintained it was not one he normally used
Hadley accepted he had not provided copies of any text messages to the court, despite a subpoena directing him to do so.
Text messages between Hadley and the staffer were produced by the complainant.
Pressed on whether he harboured animosity towards Jones at the time of the staffer's report, Hadley replied he probably had.
"I wasn't happy with him," he told the court.
The slur came after an expletive-laden confrontation between Hadley and his station stablemate over a false assault allegation.
Hadley testified he was informed he was accused of assaulting a co-worker in their workplace corridor.
However, he told the court the allegation went nowhere because CCTV footage made it clear Hadley was not close to his accuser.
He rejected the suggestion that he had assumed Jones was involved in the allegation, telling the court it had been laid out for him by a "double agent" colleague.
"(He) assured me Jones had marshalled the troops and said, 'dig up some dirt on Hadley'," Hadley insisted.
He agreed he told police he later stormed into Jones's office and called him a "dog and a c***", which he characterised as "advice" about his rival's work.
It came on the heels of Hadley being dumped as breakfast show host, which he told the court he was happy about.
He earlier signed a "secret contract" worth $4 million to take over the role from Jones, whose contract was coming to an end, he said.
"I didn't pursue it - they came to me," Hadley told the court.
"The money made me do it."
Only a few executives knew about the contract, ultimately torn up when the chairman of Nine - which owns 2GB - insisted Jones be brought back as breakfast host, he said.
"Inadvertently, Mr Jones had doubled my salary for doing the same job," Hadley told the court, insisting he was not bitter.
The contentious relationship has been laid bare as Jones's legal team argue rivalry is at the heart of the case against him.
Ms Bashir suggested Hadley wanted to destroy rival Jones and encouraged the radio staffer to make a complaint to that end.
The radio staffer strongly denied suggestions he fabricated the indecent assault claims or came forward to benefit Hadley, insisting he didn't view him and Jones as rivals.
Jones denied all of the charges, which are alleged to have occurred during the latter part of his 35-year broadcasting career, when he dominated Sydney's airwaves and won the breakfast slot a record 226 times.
The once-powerful voice in the court of public opinion also broadcast to a national audience for years as a regular commentator on Nine's Today show and a host of a political discussion show on Sky News.
1800 RESPECT (1800 737 732)
National Sexual Abuse and Redress Support Service 1800 211 028
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