Guys, Homer knew the ball doesn't leave exactly at right angles to the Clubface, espcially with higher compression shots (e.g. driver). That's what he said "practically at right angles...". I have no data to back myself up, but maybe somebody with a high speed camera or launch monitor can have some input here...I'm pretty sure it's more 1-2 degrees off 90 degrees with my driver.
Here's a thought. Put a ball on a tee. Strike a downward blow with a nine iron. Did the ball go up or down? Was the Clubhead path up or down? Practically at right angles.