If the flap/slat controls are found in some position which corresponds to the actual position of the flaps/slats after the accident then we know there was not a system failure and we can stop speculating on that.
Sorry - disagree
The Flap/Slat controls may have been moved between, say the rotation, and where they are now, either by the crew, the rescue teams, or the impact sequence. Ditto the Flaps / Slats which may have moved in/out at any of various points, including mechanical malfunction, and hydraulic power/fluid maybe being removed post the 1st impact point.
If the flap/slat controls are found in an inappropriate position for the takeoff conditions, then we can ascribe the failure to the crew.
If you want to hang a crew on a 3rd party leak of a judicial investigation, then fine, but please do not count me in.
If we are to conclude this was a crew error, then I would rather wait for a formal accident report
by an accident investigation, like the NW one, which not only analyses the flight path behaviour and
final positions of the controls and surfaces, but also ancillary evidence that might (or not) support whether those positions are representative of where they were immediately prior to the accident.
3 paras of the NW report deal with whether the position of the handle as found was, or might be representative, of where the crew (last) selected it. Those 3 paras represent considerable investigation and design analysis (and time) rather than a judicial inquiry leak of where the lever might be now
NoD