About that alleged 1966 Brown/Sanders sighting

Over the last 6+ decades, one of the "best" of all claimed U.S. Ivory-bill sightings was this one:

28 Aug 1966: Bedford P. Brown, Jr., and Jeffrey R. Sanders reported watching 2 Ivory-billed Woodpeckers scaling beetle-killed pines for 16 min along the fringes of Eglin Air Force Base in the Florida Panhandle (Dennis 1979).

Cyberthrush posted about the claimed sighting here, and on page 160 of his book, Jerome Jackson wrote:

Dennis searched the area and did not find the birds but considered the sighting valid.

On page 247 of his book, Geoff Hill writes:

...According to Ken Able, who was a prominent birder as well as ornithology professor at the time, Brown and Sanders were active birders in the Chicago area in the 1960s and 1970s. They nearly always birded together, and over a period of several years they reported a number of very rare birds around the Chicago area. Ultimately, these reports were shown to be fraudulent, Brown and Sanders confessed, and a long retraction of records appeared in the pages of Audubon Field Notes, the forerunner of North American Birds. The 1966 ivorybill sighting along the Yellow River occurred during the time of the incidents in Chicago.

Notes from a guy named "Ken Able" appear on Hill's website here. Able heard some toots in the forest last month and was moved to write:

...Could these calls have been made by a blue jay or something else other than an ivory-bill? Of course, anything is possible. Personally, I am convinced that they were made by an ivory-bill.

Update: A related post from BINAC is here.