Whatever tragic events occurred--no question it happened fast--probably instantaneously. With almost instantaneous communications capability via SATCOM and ACARS available on this aircraft, the fact that (as far as we know) AF Paris flight dispatch heard nothing from the crew themselves prior to the event suggests whatever the issue, things deteriorated very quickly...so quickly that the crew could not contact/advise CDG dispatch...it takes no more than a few seconds to hit the CDU and send dispatch a msg via ACARS.
One thing that comes to my mind with this tragedy is the Qantas A330 events in the past months, where the ADIRU apparantly cause very sudden/abrupt flight control movements. The one flight that landed in Exmouth suffered alot of airframe damage as a result of the sudden movements. Although some suggestions point to possible naval radio interference on that incident.