Bunt Attempt

[harmbu]

This is an honest question. I am not trying to bait anyone into an argument. I just want to know how this should have gone.

FED--Batter squares to bunt and the pitch is in on him and hits him. PU calls time and awards the batter first base. The defensive coach comes out saying, "He didn't pull his bat back. That is a strike." PU and BU got together, and after discussion, plate umpire calls the batter back and says that it is a strike. I (offensive coach) go out and here is what was discussed.

Me: Why does he not get his base?
PU: He didn't pull is bat back.
Me (turning to BU): So you ruled that he offered at the pitch?
BU: No. I ruled that he didn't pull his bat back and he (PU) said it was a strike then.
Me (turning back to PU): Why is that a strike?
PU: Because he didn't pull his bat back before the ball hit him.
Me: So you are saying that he offered at the pitch.
PU: No. I am saying that he didn't pull his bat back, so it is a strike.
Me: Simply not pulling your bat back is not offering at the pitch.
PU: In my opinion it is. That's it coach.

At this point, I could see that I was getting nowhere and returned to the third base coaching box.

My main question is, have I alway mistaken the rule that you have to actually offer at the pitch and simply not pulling your bat back is not an offer?

If I am correct, could someone please give me a rule reference (or preferrably a case play) to show that I am correct.

Thanks to all.