This is a man who is legally literate enough, due to his former career as a judge, to know he can't bring a case - because he lives outside the UK.
So why is he threatening to bring a case?
The clue is in the word 'former'.
This man left his career because of his political activism being incompatible with his career.
So what is his career now? What is he seeking to achieve here.
This man is probably legally astute enough to know that a case on these grounds is likely to fail - because the case was about the Equality Act and the ruling is entirely consistent with it. It simply can not make sense if sex is not biological. There would be no need to mention single sex exemptions and homosexual rights would fall apart. Not to mention that in order to be trans you have to make reference to your own sex! The problem is with the GRA not the Equality Act. 'Legal fictions' just don't work because of reality and needing definable definitions.
So what's this guy up to?
Think about it and it's obvious. He's not interested in legal recourse. He's politically not legally motivated to a point that he was forced to leave his job. His activism is everything. He threw away his career due to activism
So what gets headlines and propaganda about 'victimhood' from the SC better than threats about the ECHR? Erm... Pretty much nothing really.
This man isn't interested in the law and legal merits (or otherwise) relating to the SC ruling.
This is a guy trying to establish a new career as an activist. He's effectively 'gone viral'.
And that's what this is about - making a name for himself as an activist and profiting in someway from the publicity and notoriety.
It is not about the law. This is a political move.