Gable Tostee is not the "cartoonish villain" he has been portrayed as in the media but someone who acted in a "gentlemanly" way to an increasingly erratic woman in his apartment, his defence lawyer said on Friday.
Saul Holt, QC, has commenced his final address to jurors in Tostee's murder trial in the Brisbane Supreme Court.
The 30-year-old carpet layer is charged with the murder of 26-year-old New Zealand tourist Warriena Wright, who plunged to her death from his 14th storey Gold Coast balcony while they were on a Tinder date.
The Crown has argued a "threatening and intimidating" Tostee caused Wright's death by locking her on the balcony after a violent confrontation inside his apartment and giving her no other option but to attempt to flee by climbing over the balustrade.
But Holt said though Wright's death was a tragedy, Tostee was not to blame.
"That sequence of events is a desperate tragedy but it is not murder and it is not manslaughter," he told jurors.
"Just because somebody is dead does not in itself mean someone is criminally responsible for that death."
He argued Tostee's act of locking her on the balcony, rather than an act of intimidation, was in fact a bid to defuse the violent situation between them.
"Gable Tostee was lawfully permitted to restrain Ms Wright because she attacked him with rocks ... he was acting to remove a disorderly person from his property and the law says you can do that," he said.
"Locking her on the balcony, shutting and locking the door was an act of de-escalation ... to intervene, an act that created safety, in essence, for both of them.
"How can the locking have been intimidation when there is nothing to indicate she knew he locked the door?"
Holt said it was Wright who continually attacked his client and that his response to her was measured.
"Her behaviour becomes increasingly erratic over the course of the night," he said.
"It goes well past drunk in relation to a number of conversations.
"There are things she says and things she does that are really, really strange.
"There is a randomness, unpredictability, might I say, irrationality to her behaviour that goes beyond ordinary drunkenness.
"Gable Tostee is patient with it. She's hitting him, throwing things at him, she's saying the weirdest stuff.
"She says, 'I will f***ing destroy your jaw,' and his response is patient ... gentlemanly even.
"He responds in ways that are perfectly appropriate to Warriena Wright's increasingly odd and erratic behaviour."
Holt will finish his address to jurors on Friday afternoon.
Tostee elected not to take the stand in his murder trial, or call any defence witnesses following the closing of the Crown's case against him.
In his closing on Friday morning, Crown prosecutor Glenn Cash told jurors that the sheer terror in Ms Wright's voice just before Tostee locked her on his balcony made him as culpable for her death as if he had pushed her off.
"It was terror bordering on hysteria ... what was it that must have occurred to prompt that kind of response by her," he said.
"You hear her saying repeatedly, 'let me go home, let me go home'."
Parts of an audio recording made by Tostee of the night Wright was inside his apartment have been played to the jury as part of Mr Cash's closing address.
Once again, Wright's terrified screams of "no, no no, no, no" and "let me go home" pierced the courtroom.
"He has caused her death as much as if he had pushed her from the balcony himself," Cash said.
"Her state of terror is unmistakably proven in the recording."
Cash said Wright, who had been locked out on the balcony without any of her possessions, after Tostee had previously restrained her forcibly, threatened to knock her out and to throw her off the balcony, clearly felt climbing over the balcony was her only option.
"What would drive Warriena Wright to attempt such a thing in the early hours of August 8," he said.
"The prosecution says ... fear. Fear of the defendant, fear of Gable Tostee, fear of what he would do to her if he let her back inside.
"What abject terror would drive Warriena Wright to risk such a manoeuvre ... to climb off the balcony?
"She couldn't get assistance using the telephone, that left her with two options: to go back in to engage with the man who had violently restrained her ... who had not let her go home.
"In light of what she had done and what she feared he would do, her only reasonable option, the only remaining option was to climb down the balcony, out of fear for what he would do if she came back in contact with her."
Tostee has pleaded not guilty.