I'm not a pilot, but I have come from MAN
many times on the flight deck - most of which in the more 'normal' opposite direction over london to land on the 27s.
From what you are saying, it appears that the 'odd man out' over Windsor was executing what is known in the business as the 'West Drayton Snatch'!
West Drayton ATC bring you almost overhead on 180 at LHR
with the runways East to West directly in front of you. They then give you clearance to land with a very sharp right hand down, followed by another sharp left hand down to line up on 09.
Hence, the West Drayton Snatch!
Per Ardua ad Astra! ........ Honi Soit Qui Mal y Pense!