The question is false? What's the recorded Egyptian explanation on how the pyramids were built?
You shouldn't need any official explaination; there's only one possible way the things COULD have been built and that does not involve carving that many stones, of that size.
Those blocks were POURED, and not cut. What you do is have elephants and oxen pull wagons loaded with stone chopped into 5 - 50 lb chunks in wagons to the pyramid site from the quary, dump the stuff into a form, pour something resembling cement into the mold, allow time for it to harden, and then move on to the next block. You use the sides of existing blocks as sides of the mold, meaning you never need more than three sheets of plywood or whatever their equivalent of plywood was, and you usually just need two.