philipat "There is possibly, a very simple explanation.... Check in with stolen passport (part of a group, milling around etc etc..... Go through immigration with real one? "
There is this thing called a Boarding Card??
Is the passenger list that has been published a list of passengers who booked a flight or is it a manifest of passengers who boarded the flight?
Was there cargo or passengers on board from an earlier flight?
Where did it travel from on its previous sector and how long was it on the ground at KL?