Empty tanks, not lb, kg, L and US gal uplift calculation, differing additions = half the required quantity surely couldn't happen again!
I still haven't seen any clear indication of what the intended range was before it crashed. I had thought that it was such a short time that fuel exhaustion was out of the question.
Of course the rumour of double engine failure is just that and it still leaves all kinds of possibilities including slow spool up in a tight spot.
Things would make a lot more sense if we had knowledge of the exact flight plan and regime (was it coming or going or returning)