The fact is that in Britain NONE of the convicted criminals ever die in prison unless they have been given a death sentence in the first place.
Now that capital punishments are, ( correctly, in my opinion ), in the past it is standard procedure to release any inmate that has less than three months to live so that they do not die in prison.
Al-Megrahi was just another of them !
Even IF he WAS actually guilty of that awful crime, ( which now seems very unlikely with latest evidence and the fact that the Americans actually paid the Maltese taylor to give ID evidence against him ), then the only reason left for keeping him in jail until he died would be one of vengeance. I think that we Brits and we Scots - in particular - are better than that and the release of Al-Megrahi to die in the arms of his family just proved that we do not have to act like they do and proved that even if they can not, we CAN temper justice with mercy.