The EA2003 Part 2 applies to territories with which the UK has extradition relations in place but aren’t designated as category 1 territories. Yes, there is a threshold requirement that a relationship should exist. No, that does not mean you automatically import all the language in a treaty into domestic law. It is not strange at all.
Calling it “novel”, “strange”, “contentious”, going against what “commentators” expected (who? why do we care?), etc are all pretty much just your opinion, man. All you’re really saying is that you still don’t understand how you can have two different kinds of law and have them operate in different ways, which is perfectly okay. It’s tricky. I don’t think this HN thread is going to do a better job of figuring out if the judgment is right about the EA2003 being self-contained than the actual UK appellate court system. If we dive any deeper than “there are different kinds of law and here are the ways they usually interact” then even those of us here with law degrees are out of our depth without doing way too much research for HN.
But rather than directing your ire at today’s legal reality at this judge, maybe you should be angry that the EA2003, rushed through Parliament in the wake of 9/11 with very little scrutiny as is SOP for almost all NatSec legislation floated in western democracies since then, appears to cut off the protection against extraditions of political offences for anyone — terrorists or journalists - despite this being a common exception in treaties and I think may have been a significant part of the old scheme. Just skimming old reports I think this problem may have been raised but not addressed before passage. As I said in my first post, this is a deficiency of the EA2003, not a judge making up “novel arguments” (afaik this has never been actually tested since the EA passed, so you can’t really call it novel) and creating a problem. The problem has been there for 17 years.