During my PPL training as an ATC cadet on a flying scholarship at the West London Aero club in 1973, while flying solo, I had an airmiss with an inverted aircraft in the corridor under the London TMA to the west of White Waltham. The said aircraft was at the top of a loop. I logged the registration and on my return informed the CFI who filed for me. Sitting in the club the next day in came a gentleman who started swearing at me for reporting him. Did I not know who he was? The "gentleman" was Douglas Bader.