In fact, there are hints at progression into a higher level of lithic technology in this Calico "geofact":
That "lipped striking platform" on the left looks very much as if that entire flake were detached with a single blow from a "soft hammer" (bone or antler "billet" or "baton" or soft limestone hammer)...
(Before age degraded my hand-eye coordination, I claimed to be able to make "as good a projectile point as any but the most masterful Indian". And, given suitable material, I could replicate essentially any stone tool made on this continent.)
When you've "broken as much rock" as I have, you find it quite difficult to attribute objects like the Calico artifacts to random, natural forces.
Sitting behind a desk and pontificating proves little to nothing. Try it yourself; bust some rock. You'll learn very quickly what I mean... '-)