This is a very interesting observation. The fact that the flags are on the left leg, and that the upper flag is angled, suggests that this is not a bird flagged in Hong Kong.
It is likely that it is flagged in Guangdong. If so, the lower flag should be yellow, and should be engraved. If anyone has more photos of the bird I would be very interested to see them, and if anyone else sees this bird in LV, please try to check whether you can read the number combination on the flag.