I'm not seeing anything on that stone that would lead me to believe it was altered or utilized by man.
Not trying to argue, but it looks to me like one side shows original cortex, and the other side I'm thinking shows lots of material having been removed, last pic first post.
Not to mention the damage or possible use wear on the bit area only.
My bad. I guess should have watched the the video. I couldn't see anything in the pictures but it sure looks worked in the video. I stand corrected.