[just another ref]

There is an obvious problem here that nobody has mentioned. (have they?)
If you take the position that you will be aware of a player with four fouls and take care not to foul this player out on a "marginal call" then that will lead you to lean in the other direction and allow this player to get away with something which would have been a foul earlier in the game, or, even worse, to pass on a foul on this player that might still be a foul on another player.

I find both of these possibilities to be as unacceptable as anything else in this thread.