Actually the last two NTSB media briefings were pretty clear about it and specifically mentioned the AT and the FD state the reason being that the  AT operating mode may also depend on the active FD mode The pilot flying the plane had turned off his flight director while the training captain had his flight director on Hersman said The flight director computes and displays the proper pitch and bank angles required in order for the aircraft to follow a selected pathhttpwwwsyracusecomnewsindexssfntsbpilotsofasianaflightreliedonautomaticspeedcontrolhtml