I think he was referring to Greg Flanagan. I quoted Flanagan extensively in the thread Sam took an exception to:
Why are jacket style BCD's the most common??
The quotes came from an old pdf file that appears to have originally been on the Dive Rite site. I'll append it, but here's a few relevant excerpts:
"I made my first back plate in early 1979 from a surplus aluminum road sign of unknown alloy. I traced the outline from the solid center section of the Scuba Pro BCP onto a paper stencil and transferred this onto the aluminum.... I used this first back plate on both Double 72s and Double 80s throughout the rest of Sheck's cave course with awesome results....
Vaughan Maxwell, another student in the same cave course, then persuaded me to make him a plate and I agreed, but by this time I had decided that a second set of bends running top to bottom of the plate just outboard of the center set of bends (in order to get the plate to lay flat against the tanks) was preferable to spending another afternoon of pounding with a sledge hammer. It was also at this time that I devised the harness and slot configuration that continues in use today, facilitating the use of a single continuous piece of two-inch webbing. This second back plate was completed the night before the 1979 NSS Cave Diving Section Workshop held in Branford, Florida, and was essentially the same as those produced today....
Having standardized the design with that second plate, I received requests to make more. Over the next few months, I proceeded to make additional back plates for myself, Sheck Exley, Will Walters, Dale Sweet, Steve Straatsma, Tex Chalkley, and other "old timers" of the cave diving fraternity who used them with much success, but it was my dear friend and cave diving buddy Bill "Hogarth" Main, through his relentless pursuit of cave diving, who popularized my back plate and harness as foundational components of what has simply become known as the "Hogarthian Rig".
Dive Rite has some additional details, including a photo of the plate Flanagan made for Bill Main at
The Backplate: Foundation of Technical Rigs - Dive Rite