Unfortunately, once we get to this part of the argument, it generates more heat than light... there is a counter argument of course ... Functionality-wise, any other shape hole works fine, and the trademark office took this into account. You could oblong one side of the hole slightly, and that is clearly becomes not an issue. In fact, Benchmade used to do exactly that, and advertise it was even better than the round hole. Since it's not an issue of functionality, as BM's own claims attest, the main reason is because a round hole is intrinsically associated with the quality Spyderco is associated with. Many other companies also go the route of changing the hole shape slightly.
Lum's use of the hole was licensed from Spyderco, it's not at issue.
Whatever agreement Spyderco and Benchmade came too, I imagine there's a non-disclosure associated with it, since Sal, who is normally forthcoming to a fault, isn't talking about it. I'm not sure either company is particularly happy with the resolution, but we customers are free to choose based on what we feel is right. For myself, I respect the fact that Sal licensed the wave from Ernie, and the integral lock from Reeves, even though he could have just used the integral and come up with some other wave-like mechanism (ala Cold Steel). Legal issues aside, it's behavior I respect. That brings us back to the original sentiments in this thread -- you get decide yourself what violates your feelings of right and wrong, and what type of behavior you respect and what you don't.