I think thqt if you had an official British Government memo on your desk, you'd realise. Especially a secret 'eyes only' one.
News flash! this guy was not an official British Government desk sitter, and there was no official British government memo.
It was just crap retyped on plain paper.
So where do you get "official British Government memo" from? Obviously, you are imagining it; Too many James Bond movies?