Do not forget that even though the rest may dropping out of the way of the arrow, the arrow is still connected to the string through the power stroke. The string is trying to push straight forward but the arrow may not be pointing that way at the beginning of the power-stroke. Thus you get a more pronounced ~---> as the arrow tries to correct itself. This is why drop-aways work best with a slightly stiff arrow. Borderline spines will generally show hand torque more than a stiff arrow will. IME anyway.