Graham Parish, aged 26, was found dead early the next day in an upstairs conference room in Hayes Hotel, Thurles, Co Tipperary, where he was staying.
Two staff members at the hotel, bar manager Gary Wright, aged 34, and barman, Aidan Dalton, aged 28, both of Kilfithmone, Borrisoleigh, deny the manslaughter of Mr Parish.
It is the first case of its kind under a new liquor liability law.
Pathologist Dr Stephen Finn, who carried out a postmortem examination on Mr Parish at Limerick Regional Hospital on the day he died, July 1, 2008, said death was due to acute alcohol poisoning.
Dr Finn said a toxicology test of Mr Parish’s blood showed an alcohol level of 375mgs.
He said this level was very high as a major study of 175 cases of acute alcohol poisoning deaths showed a mean average of 355mgs of alcohol in those deaths.
Dr Finn said he found no signs of vomiting or medical causes of death.
Mr Parish, from Calder Terrace in Lomeshaye village near Nelson, East Lancashire, had booked into the hotel on June 30, 2008 — his 26th birthday — when he arrived in Thurles to do work at the Dew Valley meat plant.
Simon Turner, one of five English workmates with Mr Parish on the night of his birthday, said he joined the group at about 7.30pm in the hotel bar, where they remained for the night.
Mr Parish went to the bar at about 6.30pm, As the night went on he drank quicker and issued drink “racing challenges”.
He raced others in the group downing pints of Guinness in seconds.
Later he issued another drink challenge: he would drink a half-pint of spirits against others drinking a half-pint of lager.
The group got a variety of spirits from the bar for Mr Parish, which more than half filled a pint glass.
Mr Turner said the spirits were put into a pint glass by bar staff who served the cocktail.
Mr Turner said there was a small bet of €20.
The court was told that at 10.40pm, more than four hours after Mr Parish started drinking in the hotel bar, a till receipt taken by gardaí showed that shots were bought for €30.
Another member of the birthday group, Daniel Watson said Graham Parish told them he could drink a pint of Guinness in a few seconds and he did this a number of times.
He said Mr Parish drank a number of pints with spirits and that one of the bar staff had put the spirits into the pints. Shortly after drinking the large cocktail, Mr Parish fell off his stool. Mr Watson said as Mr Parish was very drunk, they decided he had had enough and took him upstairs.
They did not get as far as his bedroom and left him in another room (the conference room), where he was placed on the floor.
He learned of Mr Parish’s death from gardaí on going downstairs the following morning and identified the body.
Aidan Doyle SC, for barman Dalton, put it to Mr Watson that his client did not put spirits into Mr Parish’s pints, to which he replied: “I can’t remember.”