Minute of a close game a DB committed a bit of holding just prior to the QB throwing the ball. I wasn't sure if it was enough to call, so i saw the play through, and the receiver ended up missing the pass just about a foot past his finger tips. So I threw the flag late, because that little deceleration the defender caused with the jersey tug was probably the difference between the incompleteion and a probable reception. Had the receiver caught it, i would have kept the flag in my pocket. In football experienced officials will often see the play through before throwing a flag on borderline infractions.