^ A 6'9" player who jumps should also be able to hit down on the ball.
Not sure that toly
is actually saying that most players will be hittng downward on the ball. He does say that the racket face is slightly
closed and the contact point is above the equator of the ball. However, if you look closely at his picture from the OP, it appears to indicate that the racket head is still moving upward at/after contact. The tip of the racket is higher in position 3 than it is at position 2 (the instant when the ball is contacted). There is still an upward brush on the ball -- (the contact lasts a mere 4-5 ms).