I was concerned about slipping up onto the blade as well, as I work around/on a river typically. I'm no longer worried after a week of use with my a100. While its not as slip proof as say a horseman with the definite finger groove/guard, its got good jimping where your pinky/ring finger hits, and for your thumb. I'd say its as safe for a stabbing cut as a knife with a definite thumb ramp, but not as safe as a knife with a deep finger relief / guard. That said I don't stab things often, and if I do its not quickly/ hard or I'm drilling with the tip.
The a100 has a lot else going for it, first off as Dinozzo said, it carries great! Its a decently sized knife that almost vanishes in the pocket. Its Asthetically unrivaled in my opinion, this knife just has great lines! Its also fits every grip I've tried just as well as any given its handle shape. All in all its just about the perfect utility knife, no wave but the tang extends to the end of the handle so you can pop it open with practice (like the burger excaliber almost) And finally, that bit of extra tang makes one hell of a bottle opener!
Overall I got mine expecting to hate it and figured I'd send it back immediately, but its kicked everything other than my tasman salt (rope/emergency pfd knife) out of use. Its a great knife, very well designed. If your looking for a self defense knife it might not be for you, but for daily hard use, or a day hike knife (replaced my izula :0 ) you can't go wrong