Ah, but here the opposition get to see a correct decision going through while retaining the option to occupy the moral high ground in order to launch an attack. What politician could resist such a juicy morsel?

My thoughts exactly! If nothing is said beforehand, the option is retained to go for the jugular
no matter what the decision turns out to be.
We know that the Labour party was rather keen to get Megrahi back to Libya, and would have done so under the prisoner transfer agreement they negotiated in 2007 if they'd been able to (despite that being a clear breach of the agreement with the USA, and Megrahi being apparently in perfect health at that time). I think we can guess which decision they favoured from that knowledge.
By saying nothing, however, they left the opportunity open to attack the decision once it was made, even though everything points to their having been in favour of it.
They also left open the opportunity to attack the contrary decision, if that had been the outcome. In that case it's likely the affair wouldn't even have registered in the USA, and Labour politicians would have been free to shout about how this disgraceful decision, quite apart from keeping a dying man locked up and consuming expensive custodial and healthcare resources to no purpose, had fatally damaged BP's oil interests and the UK's trading relations with Libya. And probably nobody in the USA would even have norticed.
They've even managed to spin it as if it was the Scottish government which was involved in the trade negotiations, and favoured release for that reason, even though that move was actually blocked by Alex Salmond in 2007.
Neat bit of politics, I grant you, but no reason why we shoudln't see straight through it.
Rolfe.