Boguing:
Watch the video... the nose comes down as a result of inertia while the aircraft is rolled ~90 degrees starboard during stall and yawing starboard in incipient spin entry.
Once the nose is below the horizon the aircraft gradually returns to level - presumably due to crew recovery effort, but still lacks flight energy, so the nose remains low because momentum keeps it there while the wings remain stalled.
Edit: Lantirn beat me to it, and perhaps put it a bit more succinctly but we're both driving at the same thing.
Last edited by Clear_Prop; 2nd May 2013 at 22:40.