Like I mentioned in the post where this came from, once the target of a spell uses his reflect magic against said spell he becomes the owner of the spell. If the reflected spell is reflected back again at the target the original caster regains control of the spell. Below is the wording of the reflect spell explaining the exchange. Ownership of the spell changes once the first reflect goes off.
When you Reflect, Bane, or Riposte an
effect that has already been Reflected, Baned,
or Riposted, the target of the effect is once again
the original target. You may never Reflect, Bane,
or Riposte an effect more than once from the
same effect.
Justin H-