I looked up the knife, and saw the page for it at CRKT website. It mentions self-defense as an application. But it seems to me that the knife is so small, using a normal grip would establish an unreliable hold on the knife. Now, there are people who have developed specialized techniques for fighting with seemingly awkward weapons. Some capoeiristas, for example, know how to hold a razor blade between their toes. But I'd think that the manufacturer's self-defense claim is pretty unrealistic for the vast majority of us.

Of course, the ad also says you can use it to construct shelter, dress game, etc. I guess that's more possible, but it'd probably be a huge pain.