Missed plate after home run

[RKBUmp]

Originally Posted by MT 73

The USA book talks about a runner who misses home plate and is assisted back to the plate as out in a live ball situation. ( Section 7 Exception E)
Where is the rule about this being true during a dead ball?

USA case play, last sentence.

PLAY 8.7-12
R1 slides and misses home plate. The on-deck batter pushes R1 back toward home plate.
RULING: The ball becomes dead when the on-deck batter assists R1 after scoring. R1 is ruled out and the run nullified. “Dead ball” runner assistance only occurs after a runner has scored. (8-7E EXCEPTION)