Lauren Biddle died suddenly, most likely of a drug overdose, at Joseph Douglas McGirr's Clifton property on October 22, 2018.
McGirr had denied supplying the 22-year-old the Class-B controlled drug MDMA, also known as ecstasy, and attempting to pervert the course of justice by burying Biddle's clothing after her death.
He was acquitted on the drug charges by a jury late last year, but found guilty on the attempting to pervert the course of justice charge.
Judge Tom Gilbert ordered McGirr serve 20 months' imprisonment for this, at his sentencing today in the Christchurch District Court.
Leave was granted by the judge for him to apply for home detention, but only to a residential rehabilitation centre.
McGirr was discharged in relation to growing cannabis.
He was acquitted on the drug charges by a jury late last year but found guilty on the attempting to pervert the court of justice charge.
During the four-day trial last year, the jury heard two accounts of what happened on that tragic night – one version from Higginson, and one from McGirr.
McGirr himself took the witness stand to explain how he was "freaking out" after witnessing someone just die "in front of my eyes" and how he buried Biddle's clothes and belongings in an act of "spiritual reconciliation".
"At no time did I ever try to hide anything from the police," McGirr told the court.
"I was very upset and shocked, affected by alcohol and drugs."
Biddle's bikini top has never been found, the court heard.
McGirr claimed he had four party pills at his house that night.
Someone had given them to him at a party, he says, and didn't know "whether it was ecstasy or some kind of herbal". To this day, he says he's not sure of the pills' "exact composition".
After crushing one up on a chopping board in the kitchen, he says he snorted the pill's powder before returning to the spa pool where he, Biddle, and Higginson had been drinking and hanging out.
Claims earlier in the trial by his friend, North Canterbury polo player Higginson, that McGirr came out of the house to the spa with three 3cm long lines of ground up "kind of blue… bluey" powder which he took for ecstasy were "absolute rubbish", McGirr said.
Higginson says it was him who pulled Biddle out of the spa and tried to revive her with CPR, while an aggressive McGirr - wearing an ankle bracelet for a drink driving conviction - refused to call an ambulance, alleging he said, "F*** off. The police aren't coming around here."
Higginson bundled her into his car and drove to the top of McGirr's steep driveway where he phoned 111 and says he continued with CPR.
Emergency services arrived quickly but Biddle was declared dead on the roadside at around 1.20am.
But McGirr said it was him – and not Higginson – who tried to save her life.
He recalled turning around and seeing an unconscious Biddle "head down in the pool".
"I immediately pulled her out and started performing CPR," McGirr said.
After a while, he thought CPR was "futile". He looked back to the spa and saw Higginson "gurgling water".
"He was, in my opinion about 30 seconds away from drowning," said McGirr, who claims he pulled him out and put him into the recovery position, saving his life.
Biddle was dead before she left his house, McGirr believes.
McGirr, "freaking and peaking", started tidying up. He placed the lid on the spa pool, put alcohol cans and bottles away, and when he was taking fish guts in a bucket outside, he stumbled across her clothes and bag. He saw her passport photo and a "huge amount of sadness" came over him.
McGirr went down the steep slope of his property "threw her stuff on the ground".
He used a shovel to cover Biddle's items with "leaves and what not" and pushed them into a cross formation, said a prayer, repeating the psalm 'The Lord is my Shepherd' and then "kind of felt like she lifted".
He said it might sound a bit weird but "when someone dies in front of you feel like you need to do something".
"It was just a peaceful moment actually, down in the native bush with her stuff ... I was pretty upset to put it mildly," McGirr said.
"I just had an innate desire to find some kind of spiritual reconciliation immediately after the event."
McGirr then had a sleep wrapped in a duvet down on the ground on his hillside property before coming up to his house at 3.30am and being met by police officers.
He claims he told an officer about the clothes immediately – and later led them to exactly where they were.
The Crown says Biddle was very drunk - nearly four times the drink-driving limit – and found with a high concentration of MDMA in her system around 15 times greater than the "normal recreational use" of the drug.
A post-mortem found her cause of death was most likely a drug overdose that caused a sudden cardiac arrest.
