Red-backed Shrike
Paul Leader and I are almost certain that this is a Red-backed Shrike - first for Hong Kong.
Main reasons are relatively small bill (similar to Brown Shrike), extensive pale fringes to tertials, incomplete eye ring, fairly bright rufous head with limited barring (heavily barred but not rufous on Tiger).
Well done twaiyi - an excellent record and a bird which a lot of people would like to see, please could you post details of where you saw it and/or contact BirdLine.
Mike Leven