Conversely, if the action is a character ducking to miss a low flying sheep, the anticipation of the eyes leading the action should be just a couple of frames. "What the...," and the next thing, he is spitting wool out of his mouth.
The only time that the eyes or head would not lead the action would be when an external force is driving the character’s movements, as opposed to his thought process. For example, if that character was hit in the back by the low flying sheep, the force of the impact would cause the body to move first, snapping the head back and dragging it behind the main action of the body.