The turn however was at a higher rate of turn requiring an angle of bank of between 30 to 32 degrees. How did the investigators work out the required rate of turn? The turn back was actually seen on military primary radar.
If the turn was at 45 degrees AoB then I could agree that the autopilot was off. I get that an AP will turn at 25 degrees but for the calculation to come up with 30 to 32 to me suggests a margin of error with the method. The difference on the PFD between 25 and 30 is very small.