@fu That is good news, but it seems to me that if US assurances that he won't be executed aren't satisfactory, they should just stop the whole extradition process and forbid any UK agency, company, or citizen to assist in capturing and exporting him.

It isn't like our government's boiling rage is going to suddenly go away. And as long as that rage exists, they'll keep trying to seize him. Legal or illegal means won't matter, and they won't hesitate to use either.