Yor rips his stolen pendant from Ukan's neck, apparently breaking the string. As he and Kalaa flee, the pendant is nowhere to be seen. After they cross the pit of bones, Yor is suddenly wearing the pendant again, with the string inexplicably intact.
As the cavemen lead Kalaa across the bridge, she looks down and sees that the pit is full of shallow water and snakes. However, in subsequent shots of the entire cave, it's clear that the pit has a plain dirt floor; no snakes or water can be seen.
The dinosaur snaps Yor's stone ax in half during the cave fight. In the next scene, Yor walks to the village with the intact stone ax on his shoulder.
After Rea escapes the collapsing cave, her necklace with the medallion includes a bone, which disappears in the next scene.
The mole on Ena's cheek disappears in a few cave shots.
When Pag shoots one of the enemy, the force of the laser blast causes the target to fall forward, toward Pag.
People don't throw clubs, they are not intended as projectiles. They are used for close combat, to club one's enemy.