I assume the John A Wilson building is marked as an enclave of sorts inside Washington DC as it was leased for 20 years in 1995 to the federal government. While I can't confirm the current status of the building, The Council of the District of Columbia located in the building names it as as being located in Washington DC. 

I just stumbled across this on wikipedia and thought it looked wierd. If there is a reason for marking it as it currently is, please disregard this note.

