The family of Mr Brian Fitzpatrick said they are appalled at the collapse of the murder trial.
The family's comments come as Mr Michael Geoghegan and Mr Richard Bourke were acquitted in the Central Criminal Court.
The case collapsed when Mr Justice Liam McKechnie ruled that certain statements taken from the two men, while detained at Blanchardstown and Finglas garda stations, should be excluded from evidence.
Mr Kevin Fitzpatrick, Brian Fitzpatrick's brother, said he is appalled that "a man can be on his way home, an innocent man, after having a few pints with his friends and be assaulted viciously for no apparent reason, and when this thing [the case] comes to trail, the whole thing collapses for reasons unclear to me".
Commenting on yesterday's decision, Labour spokesperson on justice, Mr Joe Costello, said the only way to prevent such statements being disputed is to ensure the statements are recorded on video tape.
Echoing a call from the trial judge, Mr Justice McKechnie, he said: "There was a particularly compelling case for the interviews in this case being videotaped and the persons charged were, at that time, just 15 years of age."
Mr Costello has called on the Minister for Justice to ensure all interview rooms in garda stations be equipped with video recording equipment and to set a date for the completion of this process.
"This is not the first case in recent times on which the outcome depended on statements taken in controversial circumstances in Garda Stations."
Mr Fitzpatrick said he felt the gardaí were on trial during the case and "were subjected to all sorts of questioning".
Mr Fitzpatrick was found dead on Clune Road, Finglas, having been kicked and punched by assailants.
The civil servant, who worked for the Eastern Health Board, was single and lived with his elderly mother.