This is what I argued with him, but it seems that RR wants it ruled as no extension, ie. the exception language is ignored. This would be consistent with illegal forward passes by team B after a COP ("also loss of down if by Team A before team possession changes during a scrimmage down") resulting in an apparent touchdown.
So let's say we have this:
Tie game, 4/10 @ 50 with 10 seconds remaining in the game. A punts, and the ball is muffed by B86 at the B10. In an attempt to keep B from recovering the ball, A6 kicks the ball into the endzone where it is recovered by A5. a) There is 1 second left on the clock. b) Time expires during the play.
In a, we have A's ball 4/20 @ A40, clock on the snap. We replay the down. In b, we are saying that we are replaying the down (as that is the only way to take the TD off the board), but not extending the period? This is IMO a pretty poor interpretation of a very clearly written rule, which RR could easily edit if he wanted it called the way Rom describes.