How do you think they got the mammoth to run into the trap of spears? Also, in case it turned towards you, you’d want a spear in your hands to make him turn.

Edit: judging by the picture in the post, if you couldn’t run away, you might jam the back end into the ground beside/behind yourself and hold up the point so at least he’d be wounded when he squashed you

As far as I know, the Clovis people did not make cave paintings and the people who did make cave paintings didn’t hunt mammoths.