Overruled balk call

[Paul L]

OBR 8.05(b): "If there is a runner, or runners, it is a balk when the pitcher, while touching his plate, feints a throw to first base and fails to complete the throw." (Empahsis added)

Pony game (13-14 years old), OBR. I'm BU working for the first time with one of the big dogs of our association. Pitcher's pickoff move to first (set position) is to step halfway back, ending up with pivot foot on top of the pitcher's plate, while throwing to first. Hmm, says I, if he does that and fails to throw, that's a balk.

Few innings later, I'm in C about 20 feet from the pitcher, and he does it - steps back, turns and plants the ball of his foot in the middle of the plate, and feints a throw to first base. "Balk" says I. "No, he didn't, he stepped off" says PU. "He didn't step all the way back, his foot was on the rubber", I reply. "No, he stepped all the way off, I can see that from here," PU rejoins in an incredulous tone. I keep quiet, thinking that a quiet conference between umps was not likely to lead to a positive outcome, either for the call or for me. The balk is not enforced. Two innings later, pitcher does it again, and neither of us calls the balk.

PU later tells me that on the disputed call he saw the pitcher step all the way off, and if his foot then happens to retouch the plate while making the feint, it does not matter, he has stepped off and is now an infielder. I would not call a balk for incidental contact while feinting after stepping off. But is PU right, even when the entire pivot foot is smack in the middle of the plate at the time of the feint (which is hard to imagine without the pitcher taking two steps with the pivot foot)?

Question 2: what should I have done, what can I do now, about the big dog PU overruling my call?