Some DFDR data may be in dispute. The DFDR can only record the parameters for the stab between its design positions. The NTSB first established from the behaviour of the plane that only the movement of the stab to an extreme aircraft nose down position, well beyond design parameters, could have cause the final plunge. They then used aerodynamic and load data to extrapolate the actual position the stab, roughly 10 degress AND or more. As this is not on the DFDR it may be open to dispute, even though there is no other scientific explanation.
Don't know if this data is in dispute specifically, but as Alaska is in deep denial about this crash anyway, it probably is.