Well manually turning off the FAC in this manner sounds like a very desperate attemtp to regain control of the aircraft...
That is what I said two days ago in a post that got deleted but in any event it is only one possibility. Another possibility is simply that the cpt. got angry at the flaky computer and decided to pull the plug in a fit of spite. The PF was unprepared for the reaction of the plane to this radical step and the rest is history. I don't want to believe that this other possibility is true but similar things have happened before.
