The regulation which was cited (the TSA web page) doesn't say what you say it says.

The regulation (that I read on the TSA weblink) says that the airlines cannot transport a firearm in an unlocked piece of luggage. But luggage with a TSA lock is still considered locked luggage. *You* might not consider it a secure lock, and *you* might be right. But, for the purposes of the regulation, it is a locked piece of luggage. And while it expresses a *preference* for the owner to be present, it is not a requirement.

UPDATE: See post #26 - the TSA website has changed, and my statement here is no longer accurate