If the figures for take-off Rwy 20 were correct for the weight, then the calculations would assume that rejecting the take-off before V1, would enable the a/c to stop before the runway end -if the correct RTO actions were taken. Similarly, the figures for Rwy 25R would also allow stopping before the end of the runway, although the extra length would have produced a different V1 and T/O EPR required,( for the same flap setting).
Since there have been no eye-witness accounts of the a/c rotating, the problem for the investigators is:-
a) did the loss of directional control cause the RTO? -or
b) did the RTO cause the loss of directional control?
A wheel/tyre failure often damages adjacent wheels and the resultant loss of braking efficiency can severely alter rejected take-off stopping capabilities.
Airframes break up on hard contact with terrain (runways included), but I have never heard of a "heavy" breaking up during take-off.
( No criticism of the crew is implied by the above.)