As Calvin mentioned, easy to see how it happened and I think the design stinks but...he bought it and Im still trying to figure out how he cut his finger off. I can see how it would release but it seems like it would close up into the web between index finger and thumb.
He was probably holding it like a steak knife and shoving the blade under the cable-tie and past the gut hook, then pulling back and hooking the cable-tie, cutting it. His thumb and the web of his hand would be on the back of the knife while his index finger was underneath. He pulled back once, hit the lock-release, and the blade closed toward him and over his index finger.
