Oh, for the love of honey...
Look, there's a rule here against fraud busting... and I'm really going to try here... but, frankly, I think I'm going to overstep that particular regulation by a wide margin here, mainly due to the fact that Frank Dux, along with Ashida Kim, is pretty much the best known poster boy for fraud in the modern martial arts that there is. Everything about him is invented, false, misleading, lies, and fraudulent. Most of all his "story" that he sold as a movie, and a feature article to Black Belt magazine in the 80's.
"kumite" literally translates to "entangled/intertwined/grappling hands". Most use apply the term to many of the different styles of sparring that are used in karate.
As to "The Kumite" in the movie, yes it was a real event. There was a Blackbelt article about it in the early 80's. It wasn't so much a "secret" as it was just well known.
Here is a link to an article that talks about Frank Dux that you can decide what it true, what is exaggerated and what is not true.
The Real Frank Dux - Bloodsport True Story
The whole thing is a steaming pile of garbage. The fact that anyone believes word one of this delusional fantasy of a raving lunatic is probably the most distressing aspect of this thread to me.
The man made up an instructor who didn't exist, who taught him an art that never existed. He lied about his military record and history, wore incorrect (and un-earned) medals in photos, and, when called on it, claimed that first, he'd never said he had any medals, despite being on record talking about them, then said that the photo of him in uniform he's used to back up his claims, was a "Halloween costume". He is a charlatan of the highest order, sadly these days completely convinced of the accuracy of his lies. Pretty much every aspect of his claims, his story, his history, the idea of "The Kumite", and more have been thoroughly debunked over and over again over the last few decades.
There is no credibility to anything he has ever said or claimed.
One of the most disappointing movie vs. reality stories that I've ever seen in my life lol. This uniform doesn't help either
Those poor kids....
This is typical of Dux's "ninjitsu"... nothing even remotely looking like Japanese arts, instead aping 70's Chinese "Kung Fu" movies... in form, function, and naming conventions... seriously, if anyone thought he had any credibility, or that there was any reality to his claims, this should be the end of those thoughts immediately.
Maybe I'm just projecting my dislike of the American Ninja 4 movie
Not really... where do you think Frank got the idea from? Their really nothing like any Japanese uniform at all... it's a highly bizarre take on kami-shimo... stylised for the movie... which Frank took on as evidence that his "ninjitsu" was legitimate... after all, it looked just like the (thoroughly baseless) movie version!
So... to take this back to the OP... no. Frank Dux's imaginary "tournament" (which he has contradicted a number of times, as have his friends in an attempt to help him... which is hilarious, by the way) never happened. Frank Dux, as seen in his movie, and talked about in his stories, also never happened.