Even though Antony prefaced his remark with it being "an objective view", it is very difficult to suggest that a nation-states' "Supreme Court" has acted "illegally."
It's a bit of a logical conundrum, because the Supreme Court of a country is the final arbiter of what is legal and illegal.
With that said, if the ECHR ruled against hypothetical convictions, upheld by the SISC, my uninformed opinion is that this would make it easier for Knox to fight extradition. Indeed, while theissue was in front of the ECHR one could imagine that an American court would hold their own proceedings in abeyance until that process was complete.
Then again, extradition is fundamentally a political act, not a legal one, really. An American court could perhaps rule that there were no legal roadblocks to extradition, but the decision (as I understand it) is up to the State Department.
As for Raffaele, he's the one who has to more directly live with the fact that the Italian Supreme Court, love it or leave it, is the final authority here; ECHR notwithstanding.
In a similar vein Vincent Bugliosi wrote a book on how the American Supreme Court acted "illegally" in handing the 2000 presidential race to George Bush.
The Betrayal Of America: How the Supreme Court Undermined the Constitution and Chose Our President
Why does treason never prosper? Because if it prospers, none dare call it treason!