A ground/air sensor issue looks like a good spot to be considering. That is well recorded in both the QAR and DFDR data stream. Being KAL, there will be a lot of dialog as well back to Ops by SATCOM, and crew are likely still in one piece if not shorter than before. Ground/Air sensing has messed up landings on various aircraft previously, usually is memorably bad outcome. Smart planes don't behave well in that case, many items fail to function... like brakes (design dependent) ground spoilers, thrust reverse... just the stuff necessary to stop after landing.
FDR has a valid point. If you remember the Iberia 340-600 incident in Quito Ecuador, it suffered a very hard landing which led to loss of signalling from the main gears which then caused a lack of deployment. The aircraft was written off post removal. It is just possible that something like this happened here.