Well, I made it back to LGW, although there was a short period of concern at Lusaka (an unwell passenger had to be offloaded, causing a 40+minute delay). A bit of time was made up during the flight and the cabin crew managed to move myself and about 3 other people up to buissness for the last 30 minutes of the flight in order to help us deplane more easily. Given that we were also parked at a remote stand, the transfer went very smoothly albeit with no margin for error on this occasion. So thanks to all of you for your help from a happy traveller.