CB, ATC couldn't speak to the pilot involved, he obviously wasn't listening on 121.5 (nor was there a requirement for him to have done so). They made contact with the pilot of another civilian aircraft nearby who had the "unknown rogue" aircraft in sight. He provided useful information to them and even listening to the short exchange of dialogue from the outside, it was immediately obvious that the "rogue" aircraft, in all likelihood, posed no threat to anyone.
The RAF turned up some time afterwards.
Corporal Clott
As far as me being outraged is concerned, you couldn't be further from the truth. If you see a simple discussion, by someone with a slightly alternative view as "outrage", I think it's not me who has the problem.