Phil
You are right
One hopes the poster pays more attention to detail in his vocation than demonstrated here, especially if it is ATC.
But back to the protestations.
If the country is in the EU, then the airline passenger has rights to compensation under EU Regulation 261. There is no need to go to court. However, if the delay is due to bad weather (which it appears it is), then the airline can argue it is a circumstance not under their control and they do not have to pay the compensation. I would hope any court outside the EU would adopt similar sensible principles. If the passenger is suing a foreign ANSP for weather delays, I would say good luck with enforcing that one, and in this case, NATS is primarily subject to UK and European law, and not necessarily that of non EU countries where it does not operate.
Under the same jurisdiction, NATS would not necessarily have to deliver a report to a foreign court. They may chose to provide it to one of their airline customers though, to assist as part of their defence. Or it may have been provided through Eurocontrol who have overall responsibility for managing the ATFM network and regulations throughout the ECAC Region.
And finally, to assist you with the 'ominous' detail, here's what the original poster said:
it's a district court in some ominous eastern-European country
