I think the BOURC and the BBRC have shown great courage in today announcing the Druridge Bay Slender-billed Curlew as not proven. This means that the species is now probably considered extinct. I have no axe to grind either was but the record was contentious from the very beginning and with hindsight might better have been dealt with as not proven from the start or at least pended (though the latter would have pleased no one I guess). See here on the BBRC website.
There was however a much more recent claim from the rarity hotspot of Stronsay… see this old post by The Drunkbirder.