I think the BEA checked with Airbus and Germanwings about how the cockpit door for this aircraft was programmed, apparently the normal access code generates a buzzer for only 980ms and they ruled out completely that a 'clacking' noise heard during the 980ms buzzer was the switch being set to LOCK. The noise probably was Lubitz doing something at that point in the process of locking the door and preparing himself for what he was about to do.