Hector Enrique Valencia Valencia has been found not guilty of murdering Kimberley McRae at her Coogee apartment between January 7 and 14, 2020, but guilty of her manslaughter.

Valencia killed the 69-year-old in a rage after discovering she was transgender.

Justice Dina Yehia told the NSW Supreme Court on Friday she could not be satisfied that he intended to kill her but accepted the act was unlawful.

"It should be clearly understood that Kim McCrae was entitled to live her life. That she died is tragic," the judge said.

Valencia had testified that he was embarrassed about being intimate with a "man" because of his religion, Justice Yehia said.

He was studying business in Australia at the time when he had arranged to obtain sexual services by answering an online ad from Ms McRae.

Defence barrister Claire Wasley had argued he did not intend to kill Ms McRae, having only "lost self-control".

The Crown rejected this and did not accept his guilty plea to manslaughter before a judge-alone trial.

Valencia punched her in the stomach and face then wrestled her to the ground after he punched her.

When giving evidence, Valencia said he held a broken lamp cord against her neck because he was scared and wanted to stop the attack.

Ms McRae allegedly attempted to choke him with the cord, he claimed.

"It is not surprising that she sought to defend herself by arming herself with whatever was close to hand," Justice Yehia said, acknowledging Valencia attacked first.

A broken bedside lamp with a severed power cord was found near Ms McRae's body when it was discovered.

Ms Wasley asked NSW Health forensic pathology specialist Allan Cala if a surgery Ms McRae had to thin the appearance of an adam's apple could mean her thyroid cartilage was "not as robust".

"It might have happened in that way but it would be an unusual cause," Dr Cala said.

"I accept that it is theoretically possible."

Justice Yehia accepted asphyxiation by neck compression as the cause of death.

In a chat on Facebook Messenger to a friend on January 10, Valencia explained why he was suddenly departing Australia.

"I threw my life away, dude. I am escaping because I do not want to end up in jail in Australia," he wrote in a post translated into English.

"I die of shame to tell this to anybody. I believe I killed a whore."

He did not tell his friend Ms McCrae was transgender because he was "embarrassed".

Valencia will return to court for sentence on May 5.

Australian Associated Press