I agree with you on that point.
This is not a case of "just being a passenger on a bus". This was a bus route specifically to enter federal property where you are required to show ID.
The route was made to accommodate people going to the federal center. She could easily have taken alternate route that didn't pass through the facility. She made a choice, knowing all that.
Had she been sitting on a park bench minding her business I'd agree. She was refusing to show ID, would have to exit the bus before it went on the grounds and refused (became belligerent I think was the term).