In a "mind-construct", so to speak, if the crankshaft pulley were a sloppy fit (by way of its keyway) onto the crankshaft, and it is the crankshaft itself that causes the pulley to rotate, and to the extent the bolt behaves as if it were fixed to the pulley... then in my mind's eye, the ccw turning crank self-tightens the crank bolt... as u said above.
