ajohn

Yes, this must a HK bird. It's unusual to get records away from the Deep Bay area, and I'm sure this must be the first from Sha Tau Kok. Could you see if the flags were fresh - we have flagged a few GSP this autumn, but it is perhaps more likely that this is a bird flagged in a previous year.

ajohn

John, I think the first of your pictures shows the flag combination black over white, indicating a bird flagged in Shanghai.
The second is from Australia, and the lettering will be unique to this individual. If you contact the AWSG (http://www.awsg.org.au/index.php), they should be able to provide more details of this individual.