Mainland Japanese of Samurai lineage don't just allow anyone to suddenly refer to themselves as Samurai, you were born into that status or so I have been led to believe. The Japanese only came to direct their influences on Okinawans in the 1600's when they decided to "conquer" them and subjugate the peoples as Japanese citizens.
I believe that Okinawans, before edged weapons were removed by their King, had a military of sorts but I doubt they were considered Samurai. Even if they were the word doesn't fit because Okinawans didn't speak Japanese. They spoke a uniquely Okinawan dialect, uchinaguchi. I also doubt that they insisted they be called Samurai during the more heated times when Japanese Samurai governed or policed the island. This smacks of the audacity we Americans have when we speak of ourselves as Samurai simply because we practice with a sword.
Is this some urban type legend that was used to spruce up the stories that are told of the masters of old? When does fact fade into fiction in any story of martial arts? Isn't it natural for humans to kind of express their views with a bit of drama and dramatic license? Is this like calling myself a "warrior" when or if the term is defined could mean a yes or no?
Question, question, question .... regardless, the stories are good. I enjoy them immensely. Even if they tend to go beyond mere fact they still provide some cultural indications we can learn from so that is good, right?