With due respect to Wing, fill flash is used by many accomplished wildlife photographers to "warm up" an image in dull, flat lighting conditions, such as those depicted in the image above, or to balance lighting when the subject is side or back lit. I have used flash often in such situations and I have NEVER, to my knowledge, had a bird flush purely because of the use of flash. Let's face it, if birds flushed everytime a photographer used flash he'd very quickly learn to stop using it (or learn to make the first shot count). The use of flash seems to be becoming a very emmotive subject, but I think it's much less of a problem than it's perceived to be. I'm not defending the particular photographer concerned, who should be easily identifiable by his use of an offset flash gun (I've only seen one "bird photographer" with this set up in Hong Kong), and his overall photography and fieldcraft technique may well have spooked the Grebe, but I do want the use of flash to be seen in perspective.
However the problem of ever increasing numbers of photographers, who find it fashionable to photograph birds, but otherwise have no particular interest in their welfare, is one that needs addressing. After myself witnessing an incident in one of the boardwalk hides, in which a well known photographer appeared to flush waders deliberately in order to get flight photographs, I proposed a photographers code of conduct to HKBWS, WWF and AFCD. Lew Young was very supportive, but surprisingly HKBWS and AFCD were not, and the matter was dropped.
Until such a code of conduct is in place, with appropriate "incentives" for photographers, and birders for that matter, to comply, I would agree that finders of rarities may need to be circumspect in releasing full site details to non-HKBWS members.
Martin Hale