I ran quie by accident into this photo and I found Leica's critique interesting, as well as your critique and your reply. I think that there is nothing strange in the settings - the cause lies in metering mode - pattern mode averages the light across the whole frame. Since the bacground (which is dark) and darker parts of the bf wings occupy most of the frame area, the metering system assumed that there are poor light conditins and set longer exposure time. Looking at white spots of the wings confirm imo this. While on the orange areas you can see the details, the white ones are uniform. Look overburned. This means that while exposure conditions for the whole photo are ok, the primary photo object is overexposed. Additional evidence could be slight lack of colours saturation on the bf.
Last few days of summer (57)