Welcome to Flyertalk, TXagogo.

Hard to tell from your description exactly whether a Travel Document Checker or Behavior Detection Officer asked for your BP and ID. Either way, you're not compelled by law to play their name games. Feel free to say nothing, ask if you're free to go or state that you're not interested in being SPOTted* today.

*From the forum glossary: SPOT = Screening of Passengers by Observation Technique. Those DHS personnel who have been trained in this are known as BDO's or SPOTniks.