Ho Man Tin 30 Apr 2019 - Sakhalin Thrush? again

Ho Man Tin again before work, no Black Baza which could be my HK Tick, only the staying Siberian Thrush davisoni (?).. Comparing this: http://orientalbirdimages.org/search.php?Bird_ID=2446&Bird_Image_ID=107429 , may the molting time of both subspecies differ?

Checklist: https://ebird.org/view/checklist/S55574696

again the Siberian Thrush - a davioni??? blue when there was light and black when no....

Siberian Thrush - note the blackish blue underparts