Jason Karl Blackler (48) is on trial before the High Court at Dunedin accused of the manslaughter of 66-year-old Alan James Fahey.
The defendant allegedly got a taxi from the Brockville Rd home he shared with the victim to his then girlfriend's house in Corstorphine in the early hours of October 26.
The Crown says he killed his flatmate hours earlier during a drunken attack over sexual comments the man made about his terminally ill sister.
Blackler asked his friend Stephen Ferguson to give him a ride into town the next day.
After a trip to Probation offices in Stuart St where Mr Ferguson could not find the person his friend wanted to speak to, they continued driving around town.
Blackler requested he stop at NZCU South on Filleul St.
Teller Sheree Rusbatch told the court yesterday the defendant stumbled in at 11am and asked for $118 from his long-term savings account.
''He said he needed to go and have one last beer and some more smokes,'' the witness said.
Blackler then allegedly confessed to attacking Mr Fahey.
''He said he had beaten someone to death the night before,'' she said.
''He said he would be away for at least 10 years.''
The teller said she did not know how seriously to take the customer as he asked her whether she would call police when she left her desk to retrieve the cash.
Ms Rusbatch told the court she looked at Blackler's hands following his claims of violence but did not see anything obvious that showed he had been in a fight.
While the defendant was in the bank, Mr Ferguson was secretly texting a Probation officer to inform them of their location.
They then directed police to the scene.
Detective Constable Karl O'Dowda described how he prepared himself at the Dunedin Central station.
''After a brief discussion, I put on body armour and armed myself with a Taser and firearm,'' he said. ''There was limited information about what had taken place in Brockville and it was not clear what sort of risk Blackler posed or whether he was in possession of any weapons.''
Det Const O'Dowda and another officer found Mr Ferguson's black Chrysler in Moray Pl.
He told the jury as he was searching Blackler, the defendant made the comment: ''It's OK. There's no problem. It was just one of those one-punch things.''
The defence case is that there is no evidence Blackler had assaulted Mr Fahey or that anyone else had.
Defence counsel Anne Stevens said her client's comments came after many hours with no sleep when he was intoxicated and emotional, she said.
''What you do know is we had an older, angry, grossly drunk man in a house you will see was so messy it was hazardous,'' she told the jury.
''In that state, in that house, he could have fallen over and injured himself at any point.''
Crown prosecutor Richard Smith said at the trial's outset that there were bloody footprints leading from the victim's body to the bathroom of the Brockville Rd home, along with more blood in the basin and shower.
A postmortem revealed Mr Fahey sustained facial injuries and had long-term complaints related to lung disease from smoking and severe heart issues. Despite the pre-existing medical complaints, Mr Smith said an assault on the victim triggered his death.
The trial, before Justice Rachel Dunningham, is set to last two weeks.
