Grey-necked Bunting was in Category B ('probably wild') in the old system, based on a single record at Mai Po on 17 March 1990 - Mike Turnbull will no doubt remember.
After a detailed review by the Records Committee, it was re-assigned to Category III ('all records are likely ex-captive') in the new system. So it is not now on the HK List, which is only Category I and II species.
If no more photos or reports emerge, this record will be reviewed by the Records Committee based on the details and photograph as given.