Michael Shields' lawyers have told how they are baffled on the exact reasons why Jack Straw changed his mind and decided to release the Liverpool fan.
The Justice Secretary granted the royal pardon and stated that he now believes Michael is "morally and technically innocent".
Barrister Peter Wetherby explained that Mr Straw had been convinced of the decision upon examining "corroborative evidence".
But Mr Wetherby also told a packed press conference in Old Hall Street that the same evidence had been at his disposal for many months.
In his statement Mr Straw said that the deciding factor was when he learned that members of the Shields' family had personally heard Graham Sankey confess to the crime.
Mr Peter Wetherby said: "Strenuous efforts were made in our fight against the Bulgarian authorities, followed by the British authorities.
"We made presentations for a compelling case.
"Mr Straw has had strong evidence by way of the confession document prior to this date, as it has always been in the public domain.
"But if Mr Straw says his was a decision based upon the corroborative evidence to the confession document we are not going to argue/
"We cannot dwell on the minutiae. It is regrettable it has taken Jack Straw so long to reach this decision.
"Whe don't want to get into a political slanging match and this was by no means an easy case for Jack Straw.
"Today Michael had got justice, albeit after a lot of delay."
Michael, 22, - who has lost four stone while behind bars - described the past four years as "a living Hell".
He often appeared visibly overwhelmed with a mixture of emotions, during the press conference.
He was flanked by his team of supporters including R Reverend James Jones, Cllr Joe Anderson, Louise Elman MP and MEP Arlene McCarthy, solicitor John Weate and Peter Wetherby.
Looking relaxed Michael spoke to read a brief statement and declined to answer questions under the guidance of public relations advisors.
Michael said: "I would like to say a massive thank you to all those people out there - including Liverpool and Everton football fans - who have supported me and my family over the last four years by writing letters, by protesting, by marching.
"Your voices were heard.
"Thanks to you, I knew I would never walk alone. Thank you."
In a further statement Michael said: "Today is the first day of the rest of my life.
"Most of all I want to thank my mum and dad, my sisters, my family and friends, who never for one minute doubted my innocence and who stood by me every step of the way.
"I couldn't have made it without their love.
"Today is a happy day for me, but one of mixed emotion too.
"I am a free man, yes, but it should not have come to this.
"I now face a hard battle to adjust to normality, find a job and resume friendships. To build an ordinary life."
Michael extended his sympathy to the family of Martin Georgiev, who was the innocent victim of an unprovoked attack.
"He and his family, like me and mine, have been denied justice for four long years.
"My priority now is to spend time with my loved ones.
"To slowly begin to plan for a future as an innocent man."
angela geoghegan, liverpool around 10 months, 3 weeks ago