I think it's somewhat unfortunate. IANAL, but I think he can be extradited because the judge thinks an offense has occurred even though the CPS has decided not

I think it's somewhat unfortunate. IANAL, but I think he can be extradited because the judge thinks an offense has occurred even though the CPS has decided not to prosecute (it's what he seems to be saying here: 'Parliament has made conduct found to be contrary to S.107 (2A) criminal. No court can change the statutory offence'). Unfortunately, there's no clause in the Extradition Act in power at the moment which allows a public interest defense, so it's not the job of the judge to decide such an issue. The forum clause (linked to a bit further down) would change this.