Good analysis of what may have happened
Or is he saying it was human error
I think the plane stalled
Someone said that the survivor said he heard a loud bang after takeoff
What he's saying is that the copilot may have retracted the flaps instead of the landing gear.
Flaps and slats rotate at an angle create more surface area on the wings to help create lift at low speed, They're mandatory for take off.
Landing gear creates drag so they gotta be retracted immediately after takeoff. Landing gears being out with flaps retracted at low speed is a combination that will cause a stall. During takeoff you can see they never retracted the gear after takeoff.
The reason he believes that's more likely than an engine failure is because planes can fly with only one engine, and it's extremely rare for both to fail at the same time.