From the ATSB briefing:
"...it is important to note that in fly by wire aircraft such as the Airbus, even when being flown with the Autopilot off, in normal operation, the aircrafts flight control computers will still command control surfaces to protect the aircraft from unsafe conditions such as a stall."
and
"About 2 minutes after the initial fault, ADIRU 1 generated very high, random and incorrect values for the aircrafts angle of attack.
These very high, random and incorrect values of the angle attack led to:
the flight control computers commanding a nose-down aircraft movement, which resulted in the aircraft pitching down to a maximum of about 8.5 degrees, "
Looks like HAL took over the mothership!
(2001 Space Odyssey reference for those too young to remember).