The problems with your problem
"The problem is not what the US has done (past tense) but what the US will do (future tense). Do you really need me to point that out to you?"
There are two problems with this. First, what the US will do in the future is something which would be assessed on its merits at that time. He could be extradited to the US if there is a case to answer there. However, there is scope for the UK to refuse extradition requests from the United States, as we've seen recently. Ultimately the decision lies with UK courts and ministers. Second, you appear to misunderstand what the judge is suggesting. She is extrapolating from the time that Assange skipped bail, because he is arguing that his action of skipping bail was reasonable due to his reasonable fears. It imagines an alternate future in which Assange had actually been rendered to Sweden and then Sweden were later requested to extradite to the US. Sweden would be in no position to consider that request. It would be decided by the UK because as the extraditing country, we would still be responsible for him.