There's a large three lobed Class B airspace around Washington, Dulles and Baltimore.Then there's the special rules area (sfc to 17,999) centered on the government center. Entering this area without clearance would have been what caused all the excitement.
The president's bike ride probably resulted in a temporary restriction to the east of the Class B area. I don't know how much room there was between that area and the Class B area. Might have complicated using the VORs to the east of the Class B airspace. Other than a couple of narrow corridors, unpressurized planes maight have found it necessary to fly past the west lobe of the Class B or east over Deleware.
I'm wondering if the wayward pilots were trying to fly under the Class B between Washington and Baltimore, then turn South towards Richmond VA once past the lower section of the Class B area (& special rules area). There's a corridor there where the Class B is 2,500 to 10,000. The 139 radial from the Fredrick MD VOR would lead nicely down the corridor. A little sloppy handwriting, misread the "3" as a "5" and you would end up a little SW of the Reagan National / Pentagon area.
Robert
Near KORF