No extradition for civil judgments, so no. In principle, the successful litigant could seize any assets Musk had within reach of the UK to pay the judgment. Not sure how straightforward that would be, as it'd depend on how Musk's finances are structured and how much he travels.

Ah, right. Cheers and thank you.

Better yet, sue him in Thailand where defamation is a criminal offense where conviction comes with jail time.

and where even truth is not an airtight defense in a libel case. Thailand is not a good country in which to run your mouth on social media

That's right. Truth is not a defense at all in defamation cases. If your intent was to embarass or defame then even if what you said was true you can be convicted and do time.

Not sure if the case could be filed in Thailand. But if it was, Musk would be convicted for sure. The rescuers are all heroes in Thailand and what Musk said was very offensive and designed to do nothing other than defame the rescuer. Nothing would come of a conviction as long as Musk never visited Thailand again since nowhere would extradite him.