David,
The Pinnacle has a completely different blade shape than the Sebenza, and the handle shape differs pretty much also. The integral lock is what the two knives have in common, and perhaps that forces the design decision to use all titanium handles, another point in common. Otherwise, the knives are pretty different.
I dunno, does using the same lock constitute being a rip-off? If so, shouldn't you be saying that all liner locks are rip-offs from Walker or whoever before him invented the lock style?