This aircraft hit with very low forward velocity, from all appearances. Perhaps a spin or flat spin. Kinetic Energy goes as the square of the velocity. A spinning aircraft should have lower kinetic energy than a deeply stalled one at terminal velocity.
My physics is rusty, but isn't velocity a product of speed plus direction? A spinning aircraft may not have forward speed, but it does have plenty of changing direction, therefore plenty of velocity. So it will hit the ocean with plenty of energy, I assume?