Over the back, ON the back RM article

[M&M Guy]

Originally Posted by Camron Rust

Which is directly followed by ...

This legal use of the arms and hands usually occurs when guarding the player making a throw-in, the player with the ball in pressing tactics and a player with the ball who is maneuvering to try for goal by pivoting, jumping, etc.

"Usually", but not "limited to".

I understand the specific principle is listed in the "Guarding" section, but given the fact that verticality is also mentioned in the "Hands and Arms" section, I've been under the impression the principle of verticality applied to all players, not simply limited to ones that have obtained LGP.

What would you have, for example, in this play: A1 has inside position on a rebound, B1 is behind A1. B1 reaches for the ball over the top of A1, without displacement, and A1 reaches straight up and contacts B1's arms, knocking the ball loose from B1. Would you have a foul on A1?