It's illegal to impersonate a federal employee under these conditions: Whoever falsely assumes or pretends to be an officer or employee acting under the authority of the United States or any department, agency or officer thereof, and acts as such, or in such pretended character demands or obtains any money, paper, document, or thing of value, shall be fined under this title or imprisoned not more than three years, or both.
He didn't do any of the above.
He could have been charged here: Whoever falsely represents himself to be an officer, agent, or employee of the United States, and in such assumed character arrests or detains any person or in any manner searches the person, buildings, or other property of any person, shall be fined under this title or imprisoned not more than three years, or both.
http://blogs.findlaw.com/legalground...gal+Grounds%29
The TSA didn't make any great effort to find the two women so it became a moot point. Had the TSA felt these two were a threat to air travel, however, you can bet they would have been found.
The DA contends there is no law about impersonating a TSA screener.