Balk??

[cbfoulds]

OK, my partner @ the plate called this one in a Babe Ruth District game:

R2, outs irrelevent, RH pitcher in the Set.
Pitcher moves "differently" from his customary delivery, in that (on this occasion only) his knee comes sharply over the rubber toward 2d base; R2 dives back to bag, and F1 delivers to the plate w/o hitch or hesitation.

I've got nothing, my partner balks him for "changing his motion to intentionally decieve" R2. There is discussion w/ the coach, I try to pull my partner aside for consultation, but he isn't having any. The call stands, the coaches more or less sold by the "changed / intent to decieve" terminology. However, as I am better known to these coaches, I get some approaches later in the game, which I beg off by pleading that A) I was (must have been, didn't see the balk) doing my "sneak-a-peek" at the runner @ that moment, and B) plate ump in "better position to see" effect of this "move" on the runner.

1.) I can't find this "balk" anywhere in the book(s); am I missing something? I've always been told it is damn near impossible to balk to 2nd; and as long as the basic mechanics are legal [continuous motion after clear stop, no quick pitch, etc.], I'm having a hard time grasping how one can balk on a delivery to the plate, simply because a runner got it into his head that a pick-off attempt was coming instead [even if F1 somewhow intended to convey that impression].

2.) Presuming I am right & there was no balk, anything I could have done to "get this right"? FWIW, I am senior to this guy, but not enough so that he HAS to respect what I tell him. I was not willing to chew him out post-game without the rule book in my hand.

Thanks