This fits the TSA's "policy of unpredictability" - change, bend, or make up rules on the spot, and call it part of standard operating procedures.

On our way to LAS last month, my boyfriend left his ID in our car... at home. We got to the airport and both CO and TSA informed us that he would not be let through security, under any circumstances. They claimed that he would only be allowed to fly without ID if he were taking the return segments - on outbound flights, ID was required regardless of the explanation. In the end, I paid $75 to change his reward flights, sent someone back to our house to get the ID, and waited three hours at LAS for him to arrive on the next flight.

I have since seen many examples of people flying both outbound and return without ID. He would have dealt with secondary screening, interviews, etc. if it had meant he was able to take the original flights... that was not even on offer at BWI.