and also to the fact that AoA data is provided to BUSS - Back Up Speed tape, via the IR part of the ADIRU, in order to enter a stall the aircraft would have to have changed to Direct Law.
Which explains the Qantas incident.
P.S. - Who knows whether they (AF447) went back to normal law or not...
EDITING: The AoA is normally provided by the ADRs - The "BUSS" provides it through IR as a backup. So the doubt remains as to the role of a defective IR in the "standard" AoA output