The victim told his Linwood flatmates the next day that he felt "crook", and survived for 48 hours in his room before an ambulance was called, but he died soon after it arrived.
A flatmate had called for help for Michael Graham when he heard groaning coming from his room two days after the assault by Nathan Ihaka Te Hana.
Te Hana, 48, pleaded guilty to the charge of manslaughter in the High Court at Christchurch.
Justice Rachel Dunningham remanded him in custody for sentencing on September 21. She ordered a pre-sentence report and issued a strike warning.
Te Hana and the victim Michael Graham shared accommodation in Linwood, with two other flatmates. Te Hana and Graham lived in separate bedrooms upstairs.
On January 1, 2021, the other three were drinking heavily in the lounge. Te Hana, who does not drink, was in his room.
A woman visited and an argument developed upstairs between Graham and the woman. Graham urinated in a bottle and threw the bottle as she was walking down the stairs. It smashed at the bottom of the staircase.
Te Hana then challenged Graham, punching him once in the head and knocking him to the floor outside his bedroom. Te Hana, who was wearing socks, then stomped on Graham's head twice, causing a visibly fat ear.
Graham then used an abusive word. Te Hana returned and the woman tried to say that Graham had directed the comment at her, but Graham repeated the abusive words.
The woman said that Te Hana then stomped "really hard" on Graham's head.
Te Hana then left the flat and Graham went to his bedroom.
The next morning, Graham came downstairs and told his flatmates he did not feel well as he thought someone had "kicked me over". He said he felt crook and sore, and was going back to his room to sleep it off.
At 11am, Te Hana and an associate arrived and Te Hana asked about Graham. He said he had "lost it" and punched and stomped on Graham. He had a swollen hand. He said he was concerned that he may have killed Graham.
The afternoon of the next day, January 3, a flatmate checked on Graham after hearing groans coming from his room. He found Graham slumped down between his bed and the wall, unresponsive.
An ambulance was called, but Graham died soon after it arrived.
He had suffered a large right-sided subdural haematoma causing "left mid-line shift of the brain", and a significant right-sided subarchnoid haemorrhage with bruising to the right temporal lobe.
-By David Clarkson
Open Justice multimedia journalist
