But within minutes, Colin Wallace, 53, whose name has become synonymous with allegations of MI5 intrigue and Ministry of Defence subterfuge, heard that the Crown Prosecution Service was to seek a re-trial on the same charge.
Mr Wallace, of Arundel, West Sussex, was sentenced to 10 years for the manslaughter of Jonathan Lewis, an antiques dealer, who was found drowned in the river Arun, West Sussex, in 1980. Mr Wallace was due to meet Lewis on the night he died to discuss a friendship he had developed with Lewis's wife, but he has always denied killing him.
During Wallace's trial in 1981, the jury was told that Lewis had suffered a skull fracture while being knocked unconscious by a karate blow before being drowned. The assertion about the karate chop, made by a Home Office pathologist, Dr Iain West, was later followed by newspaper pictures of Mr Wallace, a former paratrooper, in SAS uniform, incorrectly giving the impression he had been trained in unarmed combat.
Yesterday, evidence from two other pathologists contradicted Dr West's theory. Lord Bingham, the Lord Chief Justice, sitting at the Court of Appeal, ruled the conviction unsafe and said that if the members of the trial jury were allowed to accept the karate chop theory for the skull fracture they were "plainly misled". After the hearing, Mr Wallace, who served as an army information officer in Northern Ireland until his dismissal in 1975 for handing over a classified document to a journalist, said he believed Lewis had been murdered by rivals in the antiques trade. "The police have evidence of this but have suppressed it," he said. "For the last 16 years, successive Home Office ministers have told MPs there is no reason to doubt the original findings and now key parts of the evidence have been abandoned and other parts discredited by experts."
He said he would vigorously oppose the prosecution's application for a re-trial and would seek compensation for the years he spent in prison.
The karate chop theory was contradicted by Professor Bernard Knight, also a Home Office pathologist. He told the court at a hearing in July that such a powerful blow would have damaged Mr Lewis's nasal bones, as well as causing bleeding, swelling and bruising. But there was no evidence of this.
It had been the Crown's case that Lewis had been knocked out by Mr Wallace and dumped in the river two hours later.