I had thought of that. But then it occurred to me that possibly prior to take off when relevant figures etc were being input into computers etc, if 1 pilot mad a mistake, the other would have have spotted it and pointed it out. Then, providing all was well, during the take off run, if pilot monitoring noticed that pilot flying was not doing a good job of it, he would have either pointed it out or taken direct action. I can only assume from what i have read, all went well, the aircraft departed without hitting anything; no approach lights or localiser antennae were damaged etc