For more than thirty years I have been teaching linesmen, and subsequently assistant referees, to hesitate a moment or two before raising the flag to indicate an offside infringement. Only by hesitating, I taught, could you be sure that the offside player did indeed become involved and therefore commit an infringement of law 11. And only by hesitating could you find out if it were possible to make a better decision than the obvious one of simply blowing the whistle even though you saw that the offside player did indeed interfere with play. Later, when the law was revised (to match what we were already teaching in the US in the seventies), hesitating became even more important, as it is today.
But hesitating before making any decision is also a valuable technique. I learned this from a visiting FIFA referee, Bob Matthewson of England who came over to referee in the North American Soccer League. This was before the advantage clause was revised a few years ago to give us "two bites at the apple" if we saw that the advantage we imagined did not materialize, allowing us to blow for the original free kick. Matthewson however, would hesitate at almost every decision, to look around and pick his options to make not just a good decision, but a better one, better FOR THE GOOD OF THE GAME. Take the case of the penalty-kick and the red card in the thirtieth minute of the game between Seattle Sounders and Glasgow Celtic last weekend . .