yeah its unbelievable that an experienced pilot would make a simple if huge mistake. it hardly ever happens. i was a fo lined up on rwy 1 at msy back in the day when either the chief pilot of the airline or I ( i cant remember which) stopped the takeoff roll after power application with the simple question "do we have a clearance?" not a takeoff clearance, we had that. a clearance clearance. we didnt have that. im pretty sure he was experienced and i was in a dc 9 so i had at least three years experience. how did that happen? we both eventually completed successful, and happily uneventful, 30 plus year careers.