Peter,
I am not sure what knife you are referring to. I have discussed knives with Mr. Emerson in the past. Specifically, I have put allot of time on a hawk bill that he and I were planning to make together, but to the best of my knowledge it never came to fruition. Ironically the prototype that I have is one of the knives that I wear daily.
However as often the case this may have been made without my knowledge, but that is another story.
If it is my design, then I will tell you that this design is as many of my concepts made to be effective with little training. A curved knife of this type merely needs to be placed then pulled.
This is needed for those who for whatever reason do not spend the time needed for effective traditional blade use. There are also many special techniques that are possible with this type of blade, but I cannot describe them in words only in 3D..