If he sincerely believed his life was on the line from people that were willing to creatively reinterpret the law to get him to the US, he probably wouldn't have twice waited until the day there were no further legal impediments to him being prosecuted in Sweden before changing jurisdiction.

On the other hand, insisting that superfluous assurances are made by bodies that don't have any legal authority to make them is a very good excuse for not going anywhere.