You'd win that bet. 4 weeks before yesterdays' incident both myself and my instructor were flabbergasted when an N registered posh looking twin touched down on the only (very narrow) tarmac runway at the airfield with no radio announcement on the traffic frequency.
They (4 POB) backtracked on the same runway and sat facing us for about a minute before taking off again.
There was an inversion in the area yesterday which makes me think that the 'naughty' plane was possibly using the M4 as a terrain feature. If so, that's even worse, as I thought you had to keep terrain features to your left?