Within a second of autopilot disengagement, the aircraft began to roll right and pitch down (see Appendix A - Flight Data Recorder Plot and Appendix B - Flight Data Recorder Plot - Engines). Immediately after the aircraft began to roll, it was noticed that there was ice on the left engine inlet. The roll angle increased to 64º, the pitch angle went from 15º nose up to 5º nose up, and the aircraft vertical acceleration dropped to approximately 0.5 g.
The aircraft pitch then increased to 30º nose up briefly before decreasing to 40º nose down.
These conditions are indications that the aircraft wing had fully stalled. However, the captain interpreted the indications as severe turbulence.
do you have a direct link to this AAIB report please ?