[waltjp]

Stop over thinking things. The whistle sounds the ready for play. You're really looking for trouble if you're going to start defining the length of the whistle's sound. Some refs give a quick toot. Others give a long blast. It doesn't matter. As soon as you hear the whistle it's okay to snap the ball.

Using the argument that the whistle didn't stop blowing will lead coaches to instruct their players to play until the whistle stops!