The ATSB preliminary report publishes a number of position details. It used groundspeed. The final ATSB published position reports using a "derived airspeed". Out of a combined (approx) 35 data points there are 9 in common between the 2 reports. This reveals that the ATSB have given PGW tailwind components of 7 - 23 knots both climbing away from Bankstown, in the turnaround and on descent back towards Bankstown. Its looking like the ATSB have messed up the whole airspeed element.