That's not what he's arguing. He's saying that restricting money supply as a solution to inflation only makes sense if the average price inflation represented p

That's not what he's arguing. He's saying that restricting money supply as a solution to inflation only makes sense if the average price inflation represented price movements well. His contention is that it doesn't so restricting money supply isn't a solution. I find that argument reasonably persuasive. His other point about inflation indices themselves being effectively useless, because of the inter price variability, I find less so. He skirts over the weightings which are key to the meaning of the index. They are weighted in such a way as to approximate the relative spending on each commodity. So the net effect of the index should be the inflation rate that you feel. So average measures of inflation are valuable. The standard cures likely less so.