OBR 4.09(b) revisited.

[Gee]

As we all know, the play under 4.09(b) gives the exception to the rule that a run cannot score after three outs but is it a valid exception?

"Play. Two out, bases full, batter walks but runner from second is overzealous and runs past third base toward home and is tagged out on a throw by the catcher. Even though two are out, the run would score on the theory that the run was forced home by the base on balls and that all the runners needed to do was proceed and touch the next base."

Of course the runner on third was forced to advance at the time of the walk but while the ball stayed in play subsequent action removed that force and ended the inning PRIOR TO the run scoring. Seems to me that once the force was removed it became a time play and the run would NOT score. What am I missing?