I reckon this is like how Steve Austin "designed" the Broken Skull and the Working Man. I'm sure he had his input, but he can't manufacture a knife on his own. If I had to guess, Demko probably had a heavy hand in both, since he is the expert on the triad lock. Probably the same with the Foreman grill, Air Jordans, and countless other celebrity "designs."
Two key differences in this case: 1) you are unhappy with this arrangement, 2) Jimislash claimed it's "his" design in YouTube comments.
For #1, I can understand your frustration, but that's what you get when you decided to work with this company. For #2, that was just fear of exposure and hubris talking, and I think most of us recognize that. I wish you much success in the future, as this seems like a pretty cutthroat industry to make a living in.