Curt, I'd go with Major's explanation and Ryan's great visual in my opinion. I've seen a lot of high speed shots of archery gear in action on youtube, TV etc. using professional equipment and while there is definitely a lot more oscillation than one would expect, I've never seen anything like that in all the "real" high speed shots. I don't think it would be physically possible for the string to be "ahead" of itself until after it hits brace. Think of the force of the limbs applied to the string, that's what forces the arrow, so the string would have to stay relatively in line with that force at least as long as it's in contact with the arrow...or the arrow would not move. After the limbs hit brace though you can see that type of funky gyrations pretty plainly high speed. Just my $.02.