Just because an umpiring crew makes the wrong call the entire game, when they realize it they should continue to ignore the rule. At whatever point the pitcher should be given a warning the next time is a balk.
"Here is what irritates me more - when I ask between innings about what the pitcher is doing and the umpires says "He's doing something funny but i'm not sure it's a balk". I have heard this several times over the years. My belief is there is no gray area - it's a balk or not a balk."
I'm amazed how many high school umpires can't recognize balks. The two times I'ved been tossed coaching travel was over balks not called.