I don't have an opinion one way or the other yet, but one thing I'm wondering-- why release her chained? Wouldn't there potentially be fingerprints or evidence on the restraints? Or even serial numbers that could be traced if it was industrial hose clamps? I would think, from an abductor's standpoint, you would want *less* evidence of your crime out there.
The abductors were clearly not professionals, in my opinion, and didn't think about details like this. I believe her abduction was to send a message to a known person within the family circle, and taking care of little details like serial numbers, etc were above the abductors' forethought.