The detective is correct. Assuming AAA, who sold you the pad, is also a bona fide purchaser himself, then the law governs between you and him is solely contract law, i.e., Uniform Commercial Code, Section 2, which is adopted in most jurisdictions except in Louisiana. One of the implied conditions in a sales of good contract is that the seller must have good title. Since the pad was stolen, nobody in the chain has good title to it, including AAA. Under the circumstances, AAA breached the contract between you and him by not fulfilling the above implied condition and you are entitled to damage, i.e., your purchase price. I suppose you could take the owner to a small claim court to recover the money paid.
Now, there are several problems. One, if the owner is in a different state, then you may have to go to his state to sue since courts in your state may not be able to assert personal jurisdiction over him. Second, I suppose when you bought the pad from CL there was no written contract. If the pad is over $500, then that is the most you can recover. Third, you may be able to purchase a replacement and hold AAA liable as well. Finally, you may be able to recover some of the incidental expenses such as postage, etc, as well.