My own humble opinion would be that it almost certainly played a part... fatigue is not falling asleep at the wheel... although that can certainly be one of the effects. We can't know what was going on in the mind of the Capt of KLM but I think we can safely surmise that he was anxious to get back into the air as quickly as possible, he'd been on duty for a considerable time... flown to an alternate, he'd been under considerable pressure to second guess correctly a chain of circumstances he had no control over... made a decision to fuel while held on the taxi-way in order to save time at LPA if and when he arrived there... and following all this he still had no clear idea when he would be allowed to depart... all the time knowing that his 747 crammed with passengers would have major problems finding accomodation if he failed to get airborne by a certain time that was now very close indeed. Fatigue inducing circumstances ? Absolutely... and having suffered it on too many occasions I'm well aware that the brain will try to dump inconvenient data that suggests an alternative to what appears the easy, attractive and readily available option... This was a highly motivated, extremely capable professional at the top of his profession.. Fatigue can, does and will go on muddling even the best brains.... Like almost all aviation accidents, this is not the whole cause but if asked "Did it play a part ?".. my own feeling is yes, most certainly.