A former SAS patrol commander says a fellow soldier reported being bullied and having his life threatened by Ben Roberts-Smith.
The experienced sergeant codenamed Person 21 recalled supervising the trooper known as Person One while deployed in Afghanistan in July 2006.
He told the Federal Court via videolink on Monday that Person One had been transferred into his troop for a performance review following adverse assessments and a formal warning.
"Initially Person One didn't want to speak about his experience" alongside Mr Roberts-Smith, Person 21 said.
Eventually he said words to the effect that Mr Roberts-Smith threatened to "f*** me off out of the unit, and that he was "never going to be a water operator again" (referring to an elite operational section of the regiment).
"He threatened to kill me," he recalled him saying.
It follows evidence from Person One that he formally reported the decorated soldier for a years-long campaign of "ruthless and unwavering aggression".
After a failed mission in June 2006, Person One alleges Mr Roberts-Smith said if his performance didn't improve, he would get "a bullet in the back of (his) head".
Mr Roberts-Smith's lawyers contended that Person One was merely subject to professional criticism for his failings as a soldier, and that he lied about such threats.
Mr Roberts-Smith is suing The Age, The Sydney Morning Herald and The Canberra Times for defamation over reports that he committed war crimes and murders in Afghanistan between 2006 and 2012.
The publications are relying on truth as a defence.
The Victoria Cross recipient vehemently denies those allegations and accusations of bullying.
The 43-year-old testified that his comrade just wasn't "a very good soldier" who sought to cover up his poor performance.
Person 21 has completed multiple tours of Afghanistan after joining the Australian Defence Force in 1988, and steadily rose through the ranks of the SAS.
When the patrol commander received Person One he was "nervous, unsure, asked a lot of questions" but completed tasks well, he said.
With time "he came out of his shell" and "became more confident".
"(He) appeared to be relieved and more happy."
During a "contact situation", he found his demeanour "calm, collected", and recalled he followed instructions well.
"He made good decisions. He did not need to be directed or told what to do.
"Overall I was impressed by his coolness under fire."
Person 21 said his "professional opinion" was that following supervision and guidance Person One became suitably skilled for an SAS operator of his rank.
Before the patrol commander received Person One into his unit, he remembers inserting his old troop including Mr Roberts-Smith up a mountain in Chora Pass.
He said Person One and another soldier were left to "fend for themselves," and that none of the more experienced team helped with their equipment.
Person 21 remembers the troop lacked banter, and there was absence of "joking around" that he would expect of a team.
The trial continues.
