What is Experience For ... If not ???
I would not doubt that fatigue plays some part - but I ask the same question again (I strongly make the point of being a lowly Cherokee driver who rotates about 65 knots whatever) that surely as a highly experienced heavy metal driver something in the brain screams "that cannot be right" if you have a computed take off speed of 130 knots for a heavily loaded machine whose take off speed needs to be 165 knots.
At what point does fatigue overcome aviators instinct and a captains thousands of hours of experience ???
Surely if somebody had been alert enough to recognise the incorrect speeds, the berm would never have come into it.