I realise some posters may not be helicopter pilots but, given that this is a helicopter pilots forum, some of the comments in this thread are extraordinary.
Rule 5
Even if it had been a civilian helicopter, I've read nothing that leads me to believe that the pilot would have been in breach of Rule 5 (or any other regulation).
Even if he had been flying illegally, that would not entitle the gamekeeper to do what he did.
The jury, 12 members of the community selected at random, heard the crew's account and the gamekeeper's account. The gamekeeper was defended by a very senior barrister. Having considered the conflicting accounts, the jury were sure the gamekeeper endangered the helicopter and convicted him.
(It appears that the gamekeeper changed his story between arrest and trial. When arrested, he claimed the closest he had been to the helicopter was 300 metres.)
FL