The SA of the crew was already gone at 10,000’. Intentional non compliance with regard to airspeed? I doubt it, that AS exceedance points back to lack of SA. UAS, already there at 10,000 above the ground, they just didn’t know it. Blindly following the FD was a symptom of the problem.
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FDR data showed that once descent from FL100 commenced, the crew set the Bristol QNH of 1019, deployed the speed brakes and increased the ‘Selected Airspeed’ to 300 knots. This airspeed was selected despite the fact that the maximum permitted airspeed below this altitude in UK airspace is 250 KIAS.”