I really fail to see the difference between this and Russia's fine.
The UK is a misguided democracy within the usual group of countries considered "the west", enforcing stupid and broken laws in a highly questionable fashion that presents fundamental questions about jurisdiction in the modern world.
However, it is acting against an entity is cancerous enough that even the defendent is purely challenging (and getting support on) the technical legal grounds in a search for precedent.
[1]: https://www.reuters.com/world/europe/belarus-forces-vilnius-...
Even more unlikely is the crown exercising the kind of power you're talking about. Never mind that Charles isn't the King of the majority of Commonwealth countries.