.... and what was that failure: A Crew Seat Malfunction. The aircraft was airborne for 9 seconds, the takeoff roll was about 15 seconds from a rolling start and appears to be mostly limited to no control right from the start. Without seat rail stops those crew seats can roll back a long way. The most likely culprit is that the crew seat collapsed and was too low or the locking mechanism failed and rolled back too far for effective control.
This statement is pure speculation, but fits the sequence of events