Of course he doesn't have any facts to back it up, because everything he said is completely false. If we are comparing the existence of another cut of Star Wars to aliens, then Hunter is the equivalent of someone claiming he has been abducted by aliens. The conspiracy theory factor is even there, "Lucas has turned this little thing into an urban legend" and comic book writers must have seen it.
I could just as well claim there was in fact a film version of Shadows of the Empire made, and that all the actors stood and acted the same way as they did in the Shadows of the Empire comic books, which proves it exists, because the comic artists obviously saw it in order to drawn the comic the way they did.
It is not uncommon for movie adaptions of comics to include things in the story not found in the film, not just cutscenes, but even things never intended to be in the film. It is also pretty common for scenes not to appear in the panels of a comic book exactly as they appeared in the films, so the fact that the comic book characters have different poses and stances than the ones in the film, doesn't prove anything. Even if the mythical cut does exist, there would be no way to know if the stances are the same as those in the comic short of comparing the two side by side. It is easy for someone to look at the comic book and say, "Yeah! That is exactly what I saw! That was exactly what the scene I saw in the movie looked like!".