A few salient points
The NTSB concludes that the captain’s difficulty maintaining his intended airspeed during the final approach resulted in high AOAs, which contributed to the difficulties in flaring the airplane,
When the airspeed is high enough, such as the airspeed recommended in the QRH, the AOA never reaches the flight envelope protection activation threshold.
The flight envelope protections allowed the captain to pull full aft on the sidestick without the risk of stalling the airplane.
The captain’s difficulty maintaining his intended airspeed during the final approach resulted in high angles-of-attack, which contributed to the difficulties in flaring the airplane, the high descent rate at touchdown, and the fuselage damage.
The professionalism of the flight crewmembers and their excellent crew resource management during the accident sequence contributed to their ability to maintain control of the airplane, configure it to the extent possible under the circumstances, and fly an approach that increased the survivability of the impact.
the NTSB concludes that the captain started the APU, which improved the outcome of the ditching by ensuring the airplane remained in normal law and maintained the flight envelope protections, one of which protects against a stall.