A classical spin entry into the water could explain a lot if the debris dispersion can be explained by wind and currents. Reviewing the 3-view, the rudder would be blanketed by the horizontal and with the wing sweep it would wind up pretty tight. The pitots wouldn't agree due to yaw rate and the rudder would be left in limited travel. Would be a tough recovery if it was even possible with the rudder limit. Would require a fluke (500 year?) warm air column with a sideslip at the stall break tough.