Actually the commercial refered to a law around receipt of unsolicited goods. There was/is a scam where people would send office supplies, books, etc. to people under one pretense or another and then send them ridiculous invoices that would either be paid or sent to collections (like $50 per light bulb for a case of them or something). Essentially, the idea is that if a company sends you a product that you did not order then you can not only keep it but it is illegal for them to pursue you for payment.
Here is what the FTC says about this type of situation:
Q. What should I do if the unordered merchandise I received was the result of an honest shipping error?
A. Write the seller and offer to return the merchandise, provided the seller pays for postage and handling. Give the seller a specific and reasonable amount of time (say 30 days) to pick up the merchandise or arrange to have it returned at no expense to you. Tell the seller that you reserve the right to keep the merchandise or dispose of it after the specified time has passed.
Where it gets sticky is that this is not technically merchandise, it belongs to someone else and is not produced by you. That being the case, I would think that there is a possibility that keeping the item would constitute theft. I would find proof of ownership by your customer, and file a police report alleging that the recipient knowingly kept the item after you provided them with proof that it was not merchandise but rather the personal property of one of your customers.
If it was addressed to another person by name then it stands to reason that the recipient would know that the package belonged to someone else. I would look at that angle too with regards to opening someone else's mail.
