Abdel Baset Ali al-Megrahi was an intelligence agent. Since he worked for the Libyan Government, he probably did some bad things.
But he probably did not do the specific bad thing for which he was sentenced to 27 years in prison in Scotland.
He only served eight years. He was released on compassionate grounds last Thursday by the Scottish Justice Secretary, Kenny MacAskill, and flew home to Libya.
He is dying of cancer, but his release outraged the Americans whose relatives died aboard Pan Am Flight 103 in December 1988. They believe that al-Megrahi is a mass murderer who should die in jail - but that is not necessarily so.
There were also British victims of the attack, and almost none of their relatives think that al-Megrahi should have been in jail at all. As their spokesman, Jim Swire, put it: "I don't believe for a moment that this man was involved [in the bombing]."
Back in 1988-89, Western intelligence services saw the bombing of Pan Am 103 as an act of revenge. The US warship Vincennes had shot down an Iranian Airbus five months before, killing all 290 passengers, and the Iranians were getting even.
(The US was then secretly backing Saddam Hussein's war against Iran, and the Vincennes, operating illegally in Iranian territorial waters, shot down the airliner thinking that it was an Iranian fighter.)
There was some evidence for this "Iranian revenge" theory. In 1989 German police found the same kind of bomb that brought down Pan Am 103 in a house in Frankfurt that were used by the Popular Front for the Liberation of Palestine - General Command. This organisation was based in Syria, and Syria and Iran were allies, so maybe ...
But then, in 1990, Saddam Hussein invaded Kuwait. Washington needed Arab countries like Syria to join the war against Saddam so the liberation of Kuwait looked like a truly international effort. Syria's price for sending troops was removal from America's most-wanted list. Suddenly Syria was no longer the prime suspect in the Pan Am case - and if Syria was out, so was Iran.
But more Americans died on Pan Am 103 than in any other terrorist attack before 9/11. Somebody had to take the fall. Libya was the obvious candidate, because it had supported various terrorist attacks in the past.
Soon new evidence began to appear. It pointed to al-Megrahi, who had been working as a security officer for Libyan Arab Airlines in Malta in 1988. A Maltese shopkeeper identified him as the man who bought children's clothing like that found in the suitcase that contained the bomb that brought down Pan Am 103.
It was pretty flimsy evidence, but Colonel Gaddafi, Libya's ruler, was desperate to end the Western trade embargo against his country. He never admitted blame in the Pan Am affair, but he handed al-Megrahi and a colleague over for trial in a Western court.
Al-Megrahi's trial took place in 2001. His colleague was freed, but he was jailed for 27 years (in Scotland, because Pan Am 103 came down in Lockerbie). As time passed, however, the case began to unravel.
The Maltese shopkeeper who had identified al-Megrahi, Tony Gauci, turned out to be living in Australia, supported by several million dollars the Americans had paid him for his evidence.
The allegation the timer for the bomb had been supplied to Libya by the Swiss manufacturer Mebo turned out to be false. The owner of Mebo, Edwin Bollier, revealed that he had turned down an offer of $4 million from the FBI in 1991 to testify that he had sold his MST-13 timers to Libya.
One of Bollier's former employees, Ulrich Lumpert, did testify at al-Megrahi's trial that MST-13 timers had been supplied to Libya - but in 2007 he admitted he had lied at the trial.
And this year it was revealed Pan Am's baggage area at London's Heathrow airport was broken into 17 hours before Pan Am 103 took off. (The police knew that 12 years ago, but kept it secret at al-Megrahi's trial.) The theory the fatal bag was put on a feeder flight from Malta became even less likely.
All of which explains why the Scottish Criminal Cases Review Commission announced in 2007 that it would refer al-Megrahi's case to the Court of Criminal Appeal in Edinburgh because he "may have suffered a miscarriage of justice".
The review commission's decision caused a crisis, because a new court hearing would reveal how shoddy the evidence was. Happily for London and Washington, al-Megrahi was now dying of cancer, so a deal was possible.
He would give up his plea for a retrial, no dirty linen about the original trial would be aired in public, and he would be set free.
A miserable story, but hardly a unique one. A man who was probably innocent of the charges against him, a loyal servant of the Libyan state who was framed by the West and hung out to dry by his own Government, has been sent home to die.
* Gwynne Dyer is an independent London-based journalist.