In Ng Tung Chai this morning, we spotted a Golden Spectacled Warbler species. We observed it for a few minutes before it flew away in the bird wave. We think it was a Grey-crowned Warbler. The complete eye ring rule out White-spectacled Warbler. It lack wing bars, which also rule out Bianchi's. Our bird shows a greyish tint on the forehead as well, which suggest it over Plain-tailed Warbler.
I can't say I am 100% sure so I will like to hear views from other birders!!
I managed to get a few record shots before it flew off.