I might have missed it but wind shear go around and flap 15?
It appears to be a normal full power GA rather than a WEM as flap was reduced and the gear raised.
The report says that thrust was reduced after the flap overspeed protection activated, then the thrust was put back to TOGA shortly afterwards. There was a brief period where the flaps came out again until the overspeed condition returned.
What would you be experiencing on the controls if you were flying? As the aircraft is accelerating past its trim speed, there would be an increasing nose-up moment. Reducing the attitude while keeping the power on would only exacerbate the situation. At that point, recovery is only possible by removing power and/or increasing pitch (or retracting the flaps) but the opposite was done.
The -ve g into the ground is the only real clue as to why the wrong control inputs were being made. The aircraft was about as far from stalling as you can get, yet it was being treated as though this was the condition. Reduced/negative g sensitivity? Can’t rule it out yet...
It’s possible the final roll was caused by asymmetric damage to the flaps as they were well into the overspeed regime.