Before the couple reconciled, Mr Forrest set up a Go Fund Me site to help with expenses, hoping to raise $60,000 to allow him to dedicate a year to raising Leo as a fulltime solo father back in New Zealand.
The Leo Forrest Trust was set up to handle the windfall that came about.
Today, Ms Mclachlan told the court how the defendant flew her up to Auckland from the South Island after inviting her to be a trustee.
She said that after he prepared a meal, Mr Forrest left her and his wife to eat.
When he returned, he approached her. "He was in front of me and picked me up and put me over his shoulder. I said, 'Put me down, put me down'. He dropped me backwards and I landed on my head," Ms Mclachlan said.
But Mr Forrest and his wife, who also gave evidence today, gave a much different version of events.
"After dinner finished, conversation took quite a bizarre turn," Mr Forrest said. "Trina was asking all sorts of sexual questions of both of us -- completely inappropriate."
Then, he said, Ms Mclachlan gave an impromptu demonstration of her "martial arts" skills.
"The first thing I knew was being grasped by an arm and having my leg kicked out from underneath me," Mr Forrest said.
"She fell forward of me, very hard and face down."
In their evidence, all agreed that Ms Mclachlan pursued the defendant for an apology, while he told her to leave the house.
She said his frustration boiled over and he flipped a table on to her.
"It hit me across the chest and ribs," Ms Mclachlan said. "I didn't say anything. I was just standing in shock and crying."
But Ms Badalyan and the defendant told the court it did not hit her.
A tug-of-war then ensued over Ms Mclachlan's luggage, during which, the complainant said, Mr Forrest punched her in the face.
He denied this, and Ms Badalyan said she did not see it happen.
Ms Mclachlan said that during the incident, Mr Forrest had threatened to have his wife deported to Armenia and cut off from Leo and the trust money if she sided with the complainant.
But while in the witness box, Mr Forrest dismissed her words as "a fabrication".
When asked why Ms Mclachlan would have made up the allegation, he said: "I'm sure she was very embarrassed by what happened when we fell."