Audioquest can simply set a policy where they agree to ship the evidence to the agency the buyer uses to lodge their complaint against the person who sold them the bogus cables.
That can be Audiogon, a local court, etc.
They can request the cables be destroyed after the legal proceedings are complete."
That's a reasonable request. In a case like that, I don't see why they wouldn't help out. The only thing I would add is that it probably wouldn't be necessary to send the actual phony cables out to anyone. A letter from AQ stating that the cables are fake and maybe a picture should be good enough for Audiogon, ebay etc. From AQ's standpoint, it would be very foolish to send the fake cables back out to anyone unless it was absolutely necessary to do so.
The only reason I'm kind of standing up for AQ here is that so many people had negative comments without anything to back them up. It seems like in some cases, people are trying to hold them accountable for something they have little to no control over. If you don't want to get stuck with fake cables, you can always buy them from an authorized dealer. There's no shortage of AQ dealers both online and b&m. Even Best Buy sells AQ.
But Danielk141's point is certainly a good one. If it can help out anyone that got stuck with fake AQ, by all means give them a call and see if they'll help you. If I had to guess why AQ seems a little off, or vague when people call, its probably because they don't want to give the impression that the will exchange fake cables for real ones. But that's just a guess on my part.