Before the jury were sent to decide if Colin Craig defamed Jordan Williams, they were told to decide if the politician was fairly responding to an attack, if he believed what he said was the truth or his honest opinion.
In her summing up of more than three weeks of evidence, Justice Sarah Katz told the 11 jurors the key point of the case was Craig's motive when he said Williams was dishonest, deceitful and lacked integrity.
The two allegedly defamatory actions the jury must deliberate are Craig's remarks at a press conference and a leaflet about Williams sent to 1.6 million households.
For each of the two actions, the jury must decide whether Williams had proved that, because of Craig, his reputation was lowered in the eyes of an ordinary and right-thinking member of society or if he was exposed to ridicule or hatred.
If so, Justice Katz asked them if they believed the former Conservative Party leader was appropriately responding to an attack on his character after Williams revealed Craig had been sexually harassing his former press secretary.
Or was Craig predominantly motivated by ill-will and did he want to hurt Williams?
Justice Katz told the jury that if, on the balance of probabilities - which is the standard of proof in a civil case - they believed the former, then the defence of qualified privilege applied and they should rule in favour of Craig.
"That will be the end of the matter."
However, if they decided Craig was predominantly motivated by ill-will and wanted to harm Williams then they must move to whether what he said was the truth or his honest opinion, based on facts.
And if they get through all the defences for both the remarks and the leaflet and if they decide none of them were proven, then the 11 jurors must rule on what damages Craig has to pay Williams for the "injury to his reputation and the injury to his feelings".
But she warned them: "Your reputations and your feelings do not come with a price tag" and the $1.34 million total Williams sought for both actions was a ceiling and not an amount they should aim for.
They must also decide whether they should award punitive damages as a punishment for Craig for the "flagrant disregard of his rights".
Before they retired to weigh up the evidence, the jury was given a hefty "question trail" - the longest ever given to a jury in a New Zealand defamation case - which set out the "complex case" and took them through the evidence.
They were also given copies of witness statements and three copies of the transcript of evidence, which is more than 1000 pages long.
Justice Katz said they were "the sole fact-finders" of this case who, along with herself and Craig and Williams' lawyers, were the only ones who had heard all the evidence.
"You have sole responsibility for deciding fact - that is your function."
She also told them they must not be influenced by sympathy or prejudice - whether they liked or disliked any of the parties involved.
"You cannot decide based on emotion."
The verdict must be unanimous.
What the jury must decide:
For each of the two actions Craig allegedly defamed Williams by: what he said at the press conference and what he published in the leaflet.
• If yes, then they must move to:
• Was Craig appropriately responding to an earlier attack by Williams on the politician's character or was he motivated by hurting Williams?
• Was Craig telling the truth?
• Was Craig expressing his honest opinion?
• If all are no, then they must decide how much Craig should pay Williams for the injury to his reputation and feelings.
• The jury must be unanimous.
Why is Colin Craig on trial?
The defamation trial unfolded after Craig's press secretary, Rachel MacGregor, resigned suddenly just 48 hours before the 2014 general election.
The resignation was high profile and there was much speculation about why she left.
Weeks later MacGregor turned to Williams for support, and told him she had made a complaint to the Human Rights Commission alleging that Craig had sexually harassed her.
She shared letters and poems the politician had sent her. Williams then revealed the details to other Conservative Party members.
When Craig found out, he publicly claimed Williams was part of a group of "culprits" determined to have him removed as party leader through a "campaign" of "false accusations".
Williams then filed defamation proceedings in the High Court, saying he did not lie about Craig.