OAP - my understanding is that there was a period towards the end (post VC-10 pax license expiry and prior to FSTA ramp up) where the maintenance of the Afghan airbridge was prioritised above all else, due to lack of suitable alternate transport into theater.
IMO, if a fleet of 8/9 frames was struggling to maintain a twice weekly rotation then it was probably time to go.
Just my opinion of course.