As usual, one photo is enough to debunk these myth-builders....Smooth shaft? Not everywhere...
In other places along this passage, you can clearly see it was built up with blocks (you can even see the joints in the blocks) rather than drilled out of rock.
Thanks so VERY much for posting those photos, Mr. Smarty Pants Debuker! Now how am I supposed to unload all this tinfoil? /sarc
BTW, the corner angles don't look at all like "perfect right angles", either.
As to the facing stones, were they not cut slightly oversized, then ground to fit?
I wonder if the Egyptians & others used chalk to snap a cutting line? They always had 'building lines' as part of their layout & measuring tool kit. Rubbing chalk or soot into the string, stretching, and snapping wouldn't have been that hard a trick.