Murrelet mentioned something interesting about the timing of the takeoff clearance.
"Co-pilot Latiff also confirmed that the timing of the takeoff clearance gave him the impression that everything was in order."
However,if you look at the report,the elapsed time between clearance and start of the roll is relatively considerable..in the order of 80 seconds.Partly explained by the 5 kts taxi speed I know.But if their "ready" call was premature(clearly debatable),then ATC´s natural response to offer clearance(no traffic-they cant see them anyway) whilst still on NP might have induced the pilot to readily accept the picture he saw at N1/05R intersection,given the time elapsed between the two.The longer the time elapse is,the more willing he becomes to accept the notion that he is indeed on the correct runway.
If the takeoff clearance had just been issued (on the turn into N1),the pressure to accept those compelling green lights might have been less.
Perhaps an ATC can say if there is a finite time limit on a takeoff clearance?