By Paul Reynolds
World affairs correspondent, BBC News
Megrahi is the only person convicted over the Lockerbie bombing
The release of Abdelbaset Ali al-Megrahi has left a diplomatic mess that will take a lot of time and effort to clear up.
It is also not obvious that the British government has yet started to carry out this task on a systematic basis.
It has simply denied that it sought to influence the Scottish justice secretary or that commercial considerations were brought into play.
It has also argued that since it did not take the decision, it is up to the government that did to justify it.
The government that took the decision was the Scottish government, which has control over judicial affairs in Scotland.
But the problem with this approach is that the Scottish decision has ramifications for wider British interests.
Not everybody, especially the Americans or indeed the Libyans, quite understand, or want to understand, the constitutional arrangements in the United Kingdom.
The Libyans find it convenient to thank the British government as a whole because they want to improve relations with Britain as whole, and with the West in general.
Colonel Gaddafi even thanked the Queen.
For many Americans, the British government is also the one to hold responsible, though not to praise but to blame.
The chairman of the joint chiefs of staff, Admiral Mike Mullen, declared that this was a "obviously a political decision". That is a quite an accusation.
Senator Joe Lieberman picked up the claim by Saif al-Islam Gaddafi, the Libyan leader's son, that the release was connected to pending British trade deals with Libya.
"I don't want to believe that [the reports] are true, but they are hanging so heavily in the air that I hope that our friends in Britain will convene an independent investigation of this action by the Scottish justice minister to release a mass murderer," Senator Lieberman told CNN.
Quite how "our friends in Britain" - and presumably he means the government of the UK - could "convene an independent investigation" into the actions of a separate government entity remained unexplained by the senator.
One might think that US senators, with their knowledge of the separation of powers between state and federal governments in their own country, would understand the separation of powers within the UK.
The director of the FBI Robert Mueller certainly does - he fired his broadside directly at the Scottish government.
Another problem the British government needs to address is why it wanted Megrahi transferred to Libya anyway, not as a free man but as a prisoner who could continue his sentence there under an exchange agreement.
We know the importance the British government attached to this prisoner agreement, because Justice Secretary Jack Straw told a House of Commons committee in March: "Both the foreign secretary and I believe, in the interests of our judicial and wider bilateral relations with Libya, it is important to ratify [the agreement]."
Kenny MacAskill has been forced to defend his decision
The agreement was ratified in April without the committee having time to issue its own report and the chairman said it had been rushed through to pave the way for Megrahi's transfer.
British wishes have been confirmed in a letter that a Foreign Office minister, Ivan Lewis, wrote to the Scottish Justice Secretary Kenny MacAskill.
Mr Lewis was clarifying that there was no legal impediment to the use of the prisoner transfer agreement in the Megrahi case.
"I hope on this basis you will now feel able to consider the Libyan application in accordance with the provisions of the prisoner transfer agreement," he said.
In the event, Mr MacAskill did not activate the transfer procedure but granted clemency instead, on the compassionate grounds that the prisoner is dying of cancer.
But the fact remains that the British government was using the transfer of Megrahi as part of its diplomatic effort to improve trade and relations with Libya, a country it regards as having come in from the cold.
British ministers and diplomats have a lot of explaining to do yet.