Looking at the cockpit photo there are 2 `yellow-topped knobs next to the throttles..are these `engine `run/stop` controls,as they seem to be `unguarded` and could be inadvertently operated...?
Also,if the aircraft had `speedbrakes`,where/how are they operated...SWITCH,OR LEVER...?
I have spent a few years doing airtests on ex-mil jets which have speedbrakes/airbrakes on the wings or fuselage,and I would always check their operation for symmetric extension,no yaw/roll,at low speeds before high speed extension...
To me this looks like a hurried approach,and then maybe a tecnical failure,ie,flap asymmetry,same for airbrakes/lift dump,leading to the roll...or inadvertant engine shutdown..