A lot of the legal references and assertions resulting here are worthless for this specific incident, since the Sheikh's estate is actually in
Scotland. For example:
Magistrates Court ... don't have them.
Emergency Workers (Obstruction) Act ... not applicable in Scotland.
The aviation law aspects are of course relevant to the whole of the UK
That said, I am sure there are relevant legal instruments in existence which could be used to defend the crew against any legal action undertaken by the estate.