This was quite a revealing bit of the puzzle when it was announced. In short (lay persons interpretation): due to a separate issue they had with the airspeed di

This was quite a revealing bit of the puzzle when it was announced. In short (lay persons interpretation): due to a separate issue they had with the airspeed disagree indicator warning they followed the course of action for that which was to speed up the plane to prevent potential stall. You’re flying, you don’t know for certain the speed, so go a bit faster. But this meant when they had the AoA/MCAS issue they cut off the MCAS and were going too fast to be able to manually trim the aircraft due to the fact MCAS had driven the stabilizer to full deflection. At that speed and that amount of deflection and pulling back with full elevator to try keep the nose up the forces were too great to manually trim. The solution to that is to ease up on the elevator allow the nose to go down and manually trim then nose back up. But they were too close to the ground still to do that safely. So they needed the electric trim enabled, but that means having the faulty MCAS enabled which they needed off. Suggested work arounds were to set flaps to 1 while leaving the drab trim cutoff disabled which would’ve disabled the MCAS and let you still electrically trim. But even if you thought of this you can’t extend flaps at 400kt. If all this is true then this accident is definitely not as cut and dry as everyone thought initially and the solution of “just cut the Stab Trim cutout switches and trim manually” isn’t a solution in certain failure scenarios, namely this one.