How the FDR and CVR could have helped
It brings me back to the issue of the appearance of both engine nacelles in the underwater footage. No bulging of the nacelles which would be evident had they been spinning on impact, also no curling of the compressor blades. I heard when Dom said they were going to ditch the FO asserted herself and said "No we're not" I reckon the last missed approach was asymmetric (witness said it sounded "different") and the other died as they turned back in. Although they may have briefed the ditching it happened a little sooner than they thought.
Just my 20c worth.