You can only be extradited from one country to another if it's a crime in both countries. The UK High & Supreme Court looked at the charge(s), and concluded tha

You can only be extradited from one country to another if it's a crime in both countries. The UK High & Supreme Court looked at the charge(s), and concluded that if he did what was alledged in the UK, it would be a crime in the UK. One of the 4 things he's wanted for is sex with someone who's asleep. That's rape in the UK. In fact "It's only a crime in the Sweden" would have been a perfect way to legally defeat the extradition request. His lawyers tried it. It didn't work.