Excellent catch and good question. We believe this is an error based on nomenclature.
It’s true that Len Ainsworth is the father of the Australian slot machine. In the 1940s, Ainsworth dropped out of med school to work for Ainsworth Consolidated Industries, a dental-equipment manufacturing company started by his father, a dentist, ten years earlier. Ten years later, one of Ainsworth's engineers proposed retooling the machinery to produce slot machines.
The story goes that the engineer, one Joe Heywood, said to Ainsworth, "You know, we could build poker machines."
Ainsworth replied, "What’s a poker machine?"
And that, to us, is the answer to this question.
In the U.S., coin- and bill-operated gambling devices are generally known as "slot machines" (and historically, "one-armed bandits"). In England, they’re referred to as "fruit machines." In Scotland, they’re called "puggies." And in Australia, they’re known as "poker machines" or, familiarly, "pokies."
So, we suspect that when Len Ainsworth, now 94, arrived in Las Vegas a couple weeks ago to help open the American branch of his company Ainsworth Gaming Technology, someone called him the father of the poker machine, which, somewhere along the line, got mistranslated as the father of the video poker machine.
Since we’re out on a limb here, reading between the lines, if anyone knows differently, we’d love to hear from you. But from our own research into the history of the video poker machine (QoD 1/8/16), we believe that the first bona fide electric video poker machine, the Poker-Matic, was introduced by Dale Electronics in Las Vegas in 1970. Si Redd suggested to slot-giant Bally that they get into the video poker business, which rejected it. Redd quickly patented the idea and founded International Game Technology, today the world's largest gaming-device manufacturer.