You will probably find that when the programmer was putting the rnav position into the database they looked at the the maximum speed for which the procedure was designed (aircraft category) and put the point at a distance equal to 1:30 at this speed.
Since you should make appropriate adjustments for wind effects on the timing, this position should be where you start your turn anyway (if you fly at the max speed used in constructing the procedure).
The CAA person is correct of they say that one has to comply with the procedure as published (horizontal picture) and the primary reference is still the raw data. However, the RNAV system is doing the donkey work for you by starting the turn at the ideal position every time no matter what the wind.
My recomendation - compare the timing 1:30 to the distance and the procedure speed and see if they are compatible.
Recomend that you contact the database provider and get them to explain in writing the method used to position the point and you can then give the CAA this info.