Over the back, ON the back RM article

[M&M Guy]

Originally Posted by Camron Rust

Whether you call it a block or illegal use of hands is a different issue, but the rule does support the authors claim that the defender doesn't get verticality if they don't have LGP.

But what about the very next section - 4-24-1: "It is legal to extend the arms vertically above the shoulders and need not be lowered to avoid contact with an opponent when the action of the opponent cause contact."

That does seem to directly contradict the author.