He was in America then, if you go to America then you’re going to get arrested - Skylarov found that out.
The cases I listed the people were not in the country which performed the actions (dotcom in Nz but upset America, Skripal in UK but upset Russia, etc)
If you break Thai law and insult their king it’s generally good enough to simply not go to Thailand. Piss off the wrong country though and they will persue you to a third country even without extradition agreements
(Then there cases like Gary McKinnon where they try to extradite you and make your life hell even if they lose. He’d never been to America but they tried very hard to extradite him there)
If a country wants you, it will get you. If it wants to protect you, it will, if it is powerful enough. When an American killed Harry Dunn she fled and was protected by America.
The Mordechai Vanunu case is a bit different as he was convicted of treason (he leaked details of Israel's nuclear bombs while in Britain).
It makes sense for treason to apply everywhere. If that were not the case Britain could not have executed Lord Haw-Haw given that he only sent broadcasts from Nazi Germany.
USA (Kim dotcom)
Russia (Skripals)
China (Teng Bio)
Israel (Mordechai Vanunu)