I was there
I have been following this post with interest. It is certainly the most sensational and alarming post that has been listed in the 781 contributions from Vrfpilotpb.
Filing an airprox is the most sensible thing to do, also collect as much information from the visitors to the Swan that day ; there must be some 200 to choose from.
I am unable to help trace the aircraft mentioned although I was in the right place, at exactly the right time to observe the performance. The helicopter was rotors running in the paddock of the Swan.
We had entered Windermere at Bowness, having descended from overhead Ingleborough at 5000ft to 2000ft. We tracked down the western shoreline before making a left hand turn towards the Swan from the west. I pointed the Hotel out to my Friend as we passed by, and descended further to 1200ft from Witherslack towards Arnside before turning for home.
Apart from the rotors running helicopter NO aircraft were seen by the four active eyeballs in the predominantly white, distinctively cranked wing 90 MPH Jodel.