VFD:
The assessment from the video seems spot on.
From the camera angle the aircraft comes down near vertical straight into the ground.
It would be hard to transition from a normal approach and get to a vertical attitude in a 737 in 700 ft at approach speed without rolling into a vertical attitude.
Even with a flap asymmetry that stops transition of flaps should not leave you in a situation that lets the aircraft be uncontrollable.
Giving the benefit of the doubt to the pilots, it sure looks like a control panel issue.
even if you were to roll inverted and suddenly pull back on the yoke do a splits-s it would be hard for 73 to get into that attitude below 1000' unless the aircraft were to enter the initial stages of a spin ( incipient spin ) or some sort of catastrophic structural failure..