I'm really confused how the "victim" (or any passenger complainant) could be said to have an intimidating, hostile, or offensive work environment, because the airport is not their work environment.

Now, I suppose if another TSA screener filed the complaint, or maybe the janitor who was emptying the trash cans at the checkpoint, I could see that fitting a generous interpretation of the regs, because they are at work. But a passenger is not at work when going through the checkpoint, therefore the checkpoint is not the passenger's work environment, and therefore no matter how intimidating, hostile or offensive the checkpoint is, I don't see how it can be an "intimidating, hostile, or offensive work environment" for the passenger.

This is a specific difference between the case at hand and the other examples you cited, such as government employee vs. government contractor (while both are at work) or delivery person vs. receptionist (while both are at work).

Otherwise, it seems a drunk guy making a pass at a girl in a bar (both customers, not employees) would potentially be guilty of sexual harrassment. And I doubt that the law covers, or is intended to cover, that situation.