Snap problem
 

NFHS Just before the snap, nose guard slaps the ball away from the center. I flagged this as delay of game. Correct?

It would be encroachment but the penalty is the same.

I would have the umpire tell him not to do that, so it'll be USC next time.

Canadian Ruling
 

CANADIAN RULING:

At the very least, Team B offside. I could be convinced to call OC, though.

According to our state rep. for the NFHS this is either a snap infraction by A, if A did not snap the ball in one-continuous motion or encroachment by B.

If he were a jerk about it I could be too
 

So he encroached when his hand broke the plane, which it probably did moments before contacting the ball unlesss he hit the nose of the football sqarely, this caused the ball to remain dead, and then he slapped away a dead ball, which fits as delay in my book.

Thanks for the tip: Don't work ball in your state. Yeesh.

My understanding is this was the response from the NFHS.

If this came from NFHS, then I suspect the point is that the covering official must in the general case judge whether the snapper committed a snap infraction that prompted B's slapping the ball.

That answer addresses a more general case than the one in the OP, which does not mention the possibility of a snap infraction. It is still useful in answering the OP, however, where the officials incorrectly penalized a delay of game foul.

Whatever the foul, B slaps a dead ball and cannot possibly recover it. And, again, in my game unless we have a snap infraction B gets to make this "mistake" just once before being penalized 15 yards.

No argument here.