i think i am going with the idea that she retains absolute control over the lasso.

i actually would write a story where this piece of the lasso actually retains a portion of the power of the lasso. It compels people to tell the truth, but only if the holder's (said boy) heart is true and isn't trying to use it in any skeevy way.

now, if you will excuse me... someone is chopping up onions here...

I'm not crying YOU'RE CRYING!