Unless we are looking at a sudden, simultaneous, never before experienced, depolymerization of the carbon fiber composite materials that make up the tail and engine pylons, we must look for another logical modality of failure.
The sudden deployment of the left engine Thrust Reverser fits the picture of what apparently happened... and the evidence seems to comfirm it.
As to whether it was sabotage (sabatuer cuts hydraulic line to thrust reverser just before take-off) or mechanical failure (the hydraulic line to the thrust reverser breaks because of age, wear, constriction, whatever) is another question.
Timing and location suggest sabotage. The investigators need to look closely at the left hand engine and specifically at the hydraulic lines to the thrust reverser.
This is the most plausible explantion yet for this crash.