I’ve had a couple of contacts with Secret Service agents, and they were 100% professional, not at all like the agents were to this woman. I, too, would be questioning whether they were really Secret Service agents.
That was my thought, too.
If this happened to me I think I would dial 911 and ask my local police department to send someone over immediately AND use my cell phone to snap a couple of pictures of them.
Again, what are they going to do? If they try to stop you they are using undue force for innocent actions - to my way of thinking anyway.