At any given moment, during any given play, the referees can either call or not call a penalty. To call a penalty that didn’t happen, or not call a penalty that did, is how they can control the tempo and balance of a game,.. or, if they choose, the outcome.

Perhaps they might wish to improve the entertainment value of the game, or make the league more interesting overall. Or, perhaps, with the explosion of a new sports gambling industry, they are paid well to blow certain odds.

It very well could be a combination of these things; as needs see fit.

As American as apple pie.