Justice Graham Lang has finished summarising both sides of the case and the jury will now begin deliberations tomorrow.

Mansfield argued it was not a "realistic prospect" that Polkinghorne had been able to kill his wife without leaving trace evidence you would expect, like scuff marks or blood on the wall, Justice Lang says.

If he were a master manipulator, Justice Lang says the defence alleged, he would have been doing a very poor job.

Mansfield said it was not surprising Polkinghorne deleted his messages as he would not have wanted anyone to see his communications with Madison Ashton and others.

The defence also submitted Polkinghorne had looked up "leg edema following strangulation" as he found Hanna's legs in a funny position, Justice Lang says.

And Polkinghorne's holiday with Ashton after Hanna's death occurred because many of his friends had withdrawn from him after the case hit the media and she was one person who stayed in contact with him, the judge says.

Justice Graham Lang points out that defence lawyer Ron Mansfield also said the jury cannot underestimate the extent other factors were having on Hanna and the incredibly long hours she was working.

At times it appeared she was sending emails "all night" then going to work "all day", Justice Lang says the defence suggested.

Adding to this, Hanna was taking a complicated variety of pharmaceutical drugs, according to the defence. She was on the anti-depressant Prozac, the weight loss pill Duromine, zopiclone for sleep and she was drinking alcohol.

Mansfield told the court Hanna was obviously struggling and had written several emails to herself which show an insight into how she was actually feeling, Justice Lang says. 

He says Mansfield also told the court Hanna was at high risk of suicide.

Justice Lang says Mansfield emphasised that the jury can't read much into Polkinghorne's dalliances with sex workers, and she had previously participated herself.

Hanna stated in a recording that sex worker Madison Ashton liked her more than she liked Polkinghorne.

Yes, it is clear Polkinghorne consumed meth but, Justice Lang says, Mansfield questioned what it had to do with the case.

Mansfield had argued there was no evidence he used the drug in a way that his behaviour changed to be aggressive or violent.

Justice Lang reminds the jury of the defence's evidence that a lot was going on at Auckland Eye at the time, including two shareholders departing and Polkinghorne's impending retirement.

According to the defence, Justice Lang says, his snappiness was not surprising.

Justice Lang says the defence argued Hanna seems to have largely supported Polkinghorne in the issues he was facing at Auckland Eye and that she was worried about the effect it was having on him.

Justice Graham Lang now moves on to the defence submissions.

The central theme of Mansfield's defence case was that the police did not have an open mind from an early stage.

Justice Lang references Mansfield's submission that the evidence does not support homicidal strangulation and that Hanna tragically took her own life.

Dr Stephen Cordner's evidence to the jury was that in this case, there was none of the injuries normally associated with homicidal strangulation. 

Justice Lang recalls Cordner told the jury that they would normally expect to find significant injuries in the areas where pressure was applied on the neck. There might be abrasions, internal bruising, bruising to the strap muscles and fat in the neck, according to the doctor, Justice Lang says.

None of these injuries were there, which was a "highly unusual" phenomenon in Cordon's opinion.

The doctor said normally there would also be resistance injuries on the victim and the assailant. Trace evidence would normally be found under fingernails and there was none; instead the doctor submitted the findings were entirely in line with what he would expect in a suicide by hanging or partial suspension, Justice Lang says. 

Cordner accepted in theory someone could commit such as a crime without leaving injuries, but he certainly had not come across it, Justice Lang says.

The court has adjourned briefly and when it returns, the judge will begin summarising the defence case.

Justice Lang says the Crown asked the jury to look at the circumstances in which Hanna's death occurred.

If Hanna took her life late at night, she would have to search for the rope, then she'd have to go to the top of the balustrade, find the belt then hang herself.

She would also be doing so knowing she would be found with no makeup and in a robe, and the Crown asked whether this sounded like the Hanna the jury got to know.

The Crown said this was an inherently unlikely scenario, Justice Lang says.

He then points to Polkinghorne's conduct after Hanna's death, including deleting his WhatsApp history, searching how to delete iCloud history and searching the term "leg edema following strangulation" on covert search platform DuckDuckGo.

Justice Lang says the Crown also raised the traces of meth found in the ventilation system and the printer in Polkinghorne's room at Auckland Eye.

Some people at the clinic said Polkinghorne's behaviour had changed, the judge noted, and the Crown submitted that one of his colleagues had been in touch with Hanna about his concerns over Polkinghorne's conduct at work. 

Hanna told the colleague she too was experiencing issues with him, according to the Crown.

The Crown submitted there was a degree of threatening or violent behaviour before Hanna's death, Justice Lang continues.

In January 2020, the Crown said she had told her friends, the Riordans, that Polkinghorne had put his hands around her neck before, and she mimed being strangled.

This was of concern, and they tried to convince her to leave him, the Crown submitted.

Hanna also sent a text to another friend that month indicating her long-philandering husband was acting "beastly" and in another text sent immediately after said: "I need you to know, if anything happens to me..."

Justice Graham Lang says the Crown told the jury members they could look beyond the pathology and at Polkinghorne's conduct before Hanna died.

As far back as October 2018, the Crown argued, Polkinghorne had expressed an interest in moving to Australia and setting up a life with escort Madison Ashton.

Next, Justice Lang turns to the recording of Hanna in which she sets out her view of the relationship and its troubles, "although she said she still loves him".

It seems, the Crown submitted, things came to a head at Christmas 2019, the judge says.

At that stage, the Crown said, Polkinghorne was on the cusp of moving out and he told Hanna he was going to a "wellness retreat" but instead went to see Ashton in Sydney, Justice Lang continues.

This was the context in which Hanna spoke to her doctor about her suicidal thoughts and the crisis team intervened.

Importantly, Justice Lang says, she didn't act on those feelings.