Moe's hair pattern changes in many shots during his battle with the duck.
When Larry is ready to launch a mud ball at the cavemen from a branch. You can see a rock mysteriously smashing against a boulder the cavemen hide behind, even though there's no explanation who threw it.
While the stooges are fighting the other cavemen, they launch the first mud ball. It hits a caveman (Cy Schindell) in the face. As he raises his left hand to wipe his face, you can clearly see his wedding ring.
Larry's snoring is not in-sync with the other Stooges' when they are seen sleeping.