Here is a fossilized mammoth leg bone with a cut mark on it. Could be a butcher mark or could have happened by an animal post mortem. I've always thought it was a butcher mark.
My guess is that the muscles were so big that they cut them half way down and then worked their way down to the tendons so they wouldn't lose any meat. It's the opposite for what I'd do on a deer.
I put a Clovis in the cut mark and it fit. There is also a 2nd cut mark that comes off the top of the big one at an angle to the left. I wouldn't think that teeth would make a curved cut like that.