I would be interested to know why people think this is Pale Blue, and what features are being used to rule out female Verditer.
We have had several similar birds photographed in HK and claimed as Pale Blue. The consensus has always been that these are female Verditer. To me, Neil's bird looks like a typical female Verditer so if this is, indeed, Pale Blue we have been consistently misidentifying these in HK.
For the record, features leading me to conclude this is Verditer are: deep, relatively short bill without hooked tip; uniform grey underparts (no contrast between breast and belly); lack of pale forehead/supercilium; short dark legs; retained juvenile greater coverts without pale tips (I'm not sure if this is an important feature, but I would expect a cyornis to have a brown, spotted juvenile plumage).
There seems to be a lot of variability in both species across Asia, and I have never (knowingly!) seen Pale Blue Flycatcher, so it would be interesting to know why others are so sure this is Pale Blue.
By the way, I think the old HK record may be on the verge of being removed from the HK list as a possible escape, so another confirmed Pale Blue would be particularly important for HK!