Of course the calibration is wrong. The question is how wrong, and how to make it less wrong. When you are looking for fractions of a percent in performance, the signal-to-noise ratio is very low, so there is a continuous process of recalibration. Mercedes are certainly working on improving the calibration of the aero/vehicle dynamics interaction - it's part of a job they recently advertised.Recalibration? So they think they may have got it wrong?
Or calibration? Which is understandable...