Aren't you forgetting how he came to be tried in the first place? The trial would not even have been possible without Libya's co-operation.
It was Libya which agreed to the extradition of two Libyans for trial (only one of whom was convicted) and it was Libya which set the conditions of extradition:
(a) No-one else in Libya would be pursued as a suspect
(b) The two suspects would not be interviewed by the police
(c) The trial had to be held before three Scottish judges
without a jury
Those were Libya's demands, and they were agreed and met by the UK. So, we have two men extradited from Libya on the basis of
questionable evidence, who are denied a police interview and denied trial by jury. We also have a neat little clause in the extradition which says that nobody else in Libya can be blamed for the bombing.
Scapegoats ahoy!