After a six-day trial that ended last week, Gary Wright (34) and Adrian Dalton (29) were acquitted by direction of Judge Thomas Teehan at Nenagh Circuit Court of the manslaughter of Mr Parish of Calder Terrace, Lomeshaye Village, Nelson.
But according to legal sources in Dublin, it is understood prosecutors are debating whether the case should be re-tried under special legislation introduced two years ago.
Under new laws, the office of the Irish Director of Public Prosecutions can appeal to an acquittal if it believes there has been a mistaken ruling on a point of law by the judge.
Father-of-two Mr Parish had been staying at the Hayes Hotel in Thurles, Co Tipperary, on June 30th 2008, overseeing a project for Reliant Installations Ltd, Skipton, where he was an employee.
The court heard he had drunk a lethal mix of at least eight shots in one glass which were given to him by barman Dalton and overseen by manager Wright, in the Irish hotel.
On the night of his death he was celebrating his birthday and the birth of his son.
Judge Teehan said the state had proved the two had breached their duty of care to Mr Parish and their negligence was gross.
But he found their negligence was not the cause of the victim’s death as Mr Parish took the decision to have the drink.
For that reason, he had come to the conclusion “no jury, properly instructed, could safely bring in a verdict of guilty against either man”.
After the verdict, Mr Parish’s parents David and Julie said they hoped his death from alcohol poisoning was not in vain but highlighted the dangers of drink.
In a statement, the family said: “Since becoming a father he rarely drank and had restructured his work to spend more time with his family. Unfortunately this rare opportunity to ‘let his hair down’ resulted in his death and left his young family fatherless.”
A friend of Mr Parish’s wife Emma, said she was too upset to comment.
The family are now to pursue civil action against the Mulcahy Hotel group which owns Hayes.
Already the case has had an impact on the state with Irish Justice Minister Alan Shatter announcing a review of the penalties that can be imposed on publicans for serving alcohol to customers who are already drunk.
There have also been calls for mandatory training to be introduced for all bar staff and pub owners.