NCAA: out of bounds or TD when ball hits the pylon?

[bearclause]

This isn't a theoretical. During the UCLA at Cal game yesterday, Cal's Shane Vereen dove for the pylon. The ball appeared to be over the sideline (before the goal line) before he brought in back in towards the field and hit the pylon. His knee hit the ground with the ball half over the endzone and half out of bounds beyond the goal line. His body never touched any part out of bounds until the ball hit the upright pylon.

The officials called a TD.

We're having an interesting discussion on the meaning of AR 8-2-1, IV:

IV. The ball, in possession of airborne ball carrier A21, crosses the
sideline above the one-yard line, penetrates the plane of the goal line
extended and is then declared dead out of bounds in possession of
A21. RULING: Ball is declared out of bounds at the one-yard line
(Rules 2-11-1 and 4-2-4-e).

What exactly does "goal line extended" mean? I'm thinking it means the extension of the plane of the goal line outside of the sideline, while others seem to think it means that once the ball crosses the sideline before reaching the goal line, it's spotted where it crosses the sideline.