Fact: A .50 caliber sniper rifle does not cause a person to be thrown back. The mythbusters tested this in episode 38 with a pig suspended in the air, a mere poking of a finger was capable of dislodging it. They fired every manner of firearm at it and it did not fall or go flying. They then they put a bullet proof vest on the pig to maximize the kinetic absorption and achieved the same result. If that level of kinetic energy doesn't do it... I don't really see any arrow doing anything, no matter how powerful the bow nor how heavy the arrow.

As for the Texan curriculum, perhaps, in an obscure manner what you say can be deemed correct but that is decidedly not a good way to describe it. It's not a push, it's a transfer of kinetic energy. Think of a Newton's Cradle. The kinetic energy is transmitted along the balls via a conductive medium, like electricity through a wire. There's no "pushing". In this case, an arrow striking a near immovable object the kinetic energy is transmitted to immovable object but must be dispersed in some fashion. (Conservation of energy) Since it can't move the immovable object, deform the object, or otherwise do work the energy then gets transferred back to the arrow. One could call that a "push" but it's not very accurate. The wall isn't pushing you back with the same force... you're pushing against yourself; The wall is simply a conductive medium.