Of course, without badge numbers and names, all the Service would have to do is say, "No, they weren't ours", and she would be left pounding sand.
One day, they're going to try this with somebody who is prepared to record the encounter.
She is now a Freeper, and from other posts here it looks like it’s been verified that these were real Secret Service agents. It also sounds as if there is no way to prosecute the person who reported this as a death threat. They have to investigate any threat and had no way of knowing if it was a lie.
From now on I will be pushing the record button on my answering machine when campaign workers call. It would be nice to have a video recorder for any unexpected visitors at the front door too, but that would require some real cash outlay! Maybe a security camera with video backup?