This video, claiming to have been taken 5 mins after the crash, from the roof top in a nearby residential area(F-6), doesn't make the weather look that bad at all. It seems the hills are clearly visible for a CFIT.
YouTube - Air Blue plane crash at Margalla, unseen video 5 minutes after crash from F6
(though we do have to take into account whether this was really taken after 5mins of the crash and weather can change pretty quickly in the area).