It didn't help that the pilot flying was the one that made the error, and the other one, who correctly understood the situation, was the pilot monitoring. Even

It didn't help that the pilot flying was the one that made the error, and the other one, who correctly understood the situation, was the pilot monitoring. Even more, the pilot monitoring didn't explicitly take control of the aircraft - "My aircraft". Bonin was under the impression that he's in charge, and was utterly confused by the whole situation, until the end. As with each aviation accident, it's not a single cause of failure - it's a swiss cheese model of failures, where it just happened that all the holes aligned - from the flight law dropping to alternate, to Bonin who didn't trust what the computers said, to the other pilots not understanding completely what Bonin did, to the pitot tubes freezing.