Through my experiment with many people, The FILD method consistently produces false awakening. Especially if you use a variant of it -- instead of physically moving your fingers; IMAGINE the movements! The advantage of this is that it will enable you to recognize when you have a false awakening -- your fingers will start moving freely in a very convincing fashion. When this happens you know you are having a false awakening. Another advantage is that it will less likely to keep you awake, unlike the original FILD technique.