That has me wondering "where are the cushions that should have floated?"
I wonder why much more debris was not spotted, or recovered. It appears that the airplane sunk very rapidly, simular perhaps to Air Florida at MIA, leaving very little on the surface. So little, that first responders could not locate the airplane, despite very reliable electronic information and vectors.
As to belted or not, I believe at the onset of LOC that whereever an unbelted pax was if thrown from his seat, is where he remained until impact, be it on the ceiling or on the floor. I doubt full information regarding injuries has not been forthcoming, which begs the question can what has been released be relied upon to base conclusions.
Getting into September - awaiting BEA info on a continuation of the search?