Your explanation sounds good, except for, if the hijacker(s) were so sophisticated, how could they made the simple mistake of miscalculating the fuel?
Honestly? Look how many supposedly brilliant criminals get caught for a tail light violation or speeding.
With these religious fanatics, they may well have relied on Allah to make up a dew hundred gallons. I’m serious.
Fuel usage depends on range and payload and flying conditions. Unexpected head winds, flying below FL30, trying to ascend to FL45, etc. all would burn up a lot of extra fuel.
Typically these aircraft are only given enough fuel for 45 minutes extra flying time. India is a long way off, at the end of their range under normal conditions.
My guess the pilot calculated his range, saw that he couldn’t make, especially flying under FL10 to avoid Indian radar, and dove in hard to keep floating debris to a minimum.
Wasn’t it the Beagle Mars probe where braniac scientists forgot to convert miles and kilometers?
Either bad at math, can't change pounds into kilos, or both.