A man who attended the same self-help course as Rebekah Lawrence died in circumstances with "certain parallels", an inquest has been told.
The young Korean was found dead in his apartment a week after attending the course, naked with up to 10 stab wounds.
People KnowHow boss Geoffrey Kabealo said he had always understood the death to be a murder, but if, in fact, it was a suicide, he could see the connection.
"This was the evidence of one police officer, but if, indeed, it was a case of him taking his own life I can see the nexus," he said.
The inquest also heard that moments before jumping naked to her death during a psychotic episode, Rebekah Lawrence tried to contact the same self-help program that induced her "lethal psychosis".
"She herself made the connection between what was going on in her mind and the course," counsel assisting the coroner Robert Bromwich said.
He described this as "the clincher" - the reason why Deputy State Coroner Malcolm MacPherson should accept the "overwhelming" evidence that Ms Lawrence's psychosis, and therefore death, was brought about by her participation in the "extreme and abnormal" personal development course.
Ms Lawrence plunged to her death from the second storey of her Macquarie Street office building, in central Sydney, shortly before 7pm on December 20, 2005.
An autopsy found the 34-year-old had no drugs or alcohol in her system at the time of her death, which came just two days after completing a Turning Point course described as a "journey to the core of the human spirit".
Forensic psychiatrist Michael Diamond told Glebe Coroner's Court on Wednesday that Ms Lawrence had been displaying regressive, child-like behaviour immediately before her death, which he attributed to the "intrinsically unsafe" course run by People Knowhow.
"The petulant behaviour, the sing-song voice, the taking off of her clothes, the coquettishness, the child-like voice ... these are clear descriptions of regressive behaviour," Dr Diamond said.
"It was something that was actually participated in during the course, so it's difficult not to see a causal link."
Regression sessions were a normal and good part of therapy but they must take place in a safe, trusting environment, Dr Diamond said.
Undertaking them in the "risky" and "reckless" manner the Turning Point program had done was "a dangerous thing", he told the inquest into Ms Lawrence's death.
In his closing submissions to the inquest, Mr Bromwich said there had been no sign Ms Lawrence was suffering a pre-existing mental condition that could have contributed to her psychotic state.
"The evidence has revealed that it was the course, and not Rebekah Lawrence, that was extreme and abnormal ... Participants were put through a psychological wringer," he said.
"How much more dangerous, or how much more risky, would it be for somebody who does (have a pre-existing condition)?"
The "teachers" and support staff who led the course "simply didn't have a clue" how to diagnose, treat or support her, Mr Bromwich said.
"These people should not be conducting this course and some means need to be found to stop this happening.
"Ms Lawrence made many attempts to speak to someone - several attempts.
"When she finally found Mr Kabealo, he not only didn't realise something was going wrong, but he took what she said (as a positive reaction)."
It was when Mr Kabealo took the stand for the second time that he admitted this was not the only time something might have gone wrong on the course.
Mr Bromwich made three recommendations to the coroner, including greater regulation of the professional use of the terms "counsellor" and "psychotherapist", and an Australia-wide registration and accreditation system for similar courses.
The inquest continues.
