5th inning rule in Baseball when game is Rained Out

I think that rule is still there, more than half the game must be played in order for the game score to stick?

I think old rule was winning team won an unfinished rained out game?
Before inning 5 the game is null.

One fundamental what if problem I always saw

Scenario
It's bottom of the 4th inning and the home team is up 21-0, creaming the away team

Skies are darkening and it looks like it's about to pour
Batters know their score won't stick if game doesn't get to middle of inning 5

Pitcher can then pretty much take a knee, right? Kill as much time as possible between pitches to slow the game time down so the score won't count?


5th inning rule in Baseball when game is Rained Out