4. but you need to understand a very significant different: they kept the warrant secret to ensnare him. If they issued a warrant and then he visited the USA and gets arrested -- that's stupid. But he had no idea, worse he couldn't have any idea. Do you get my problem here?
Plenty of people have warrants out against them that they don't know about. Lots of jurisdictions, including developed modern Western nations other than the US, don't send you warning in advance that you're going to be arrested. They just show up with the handcuffs.
On foreign soil? They set a warrant out for you waiting for you to travel there, kept in secret? Not sending it to the home authorities? What's wrong with this picture?
As hard as it may be for you to believe, police in many countries are generally not in the habit of warning people in advance that they're going to be arrested. I know it's rude of them since it may inconvenience someone's travel plans, but that's just kinda how it is.