There are a number of errors in the commentary.
The most blatant may be on page 59. "There is no ko threat big enough" whilst strictly true, black does not need to recapture the ko.
Had black played 28 at 8 in the diagram, white 9 retakes the ko, for black connecting at 10 to save the cutting stone is enough;
as white's right-side group will struggle without benefit.