Depends on what the doctor on board told the captain. If people have baro-trauma affecting their ears and causing vertigo (which I think is what was meant in the original reports) then rapid descent and the associated rapid pressure changes may not be advisable (or advised). A slow cruise descent with slow pressure change and minimum maneuvering may be the ideal. If you are going to take over an hour or so to get down and there doesn't appear to be an acute emergency, then choice of 'suitable airport' is wide open and return to an airport which is a maintenance base starts to figure higher in the decision making. They were not far out of Scottish airspace so 7700 and direct LHR in slow descent seems eminently sensible. If things did change there were several suitable airports en-route LHR for an emergency descent and land.
You can bet that the captain was not without advice
