You dont think the Agent in Charge at the white House would recognize the voice of someone that works for him? If Master Card asks you for your mothers maiden name, last four digits of social security number, zip code, etc. you dont think the Agent in Charge couldnt ask the Agent a series of questions that only he would know the answer to?
Also ever hear of FAX or computers? The pilot wanted American to fax him photos of all known terrorists. Are you saying that within five minutes, the Secret Service couldnt fax or email either the pilot, the gate, the airline, or aiport police a full color photo of the agent.
The thing is, the situation WAS resolved, it had less to do with the agents nationality then it had to do with his threatening manner as well has his challange to authority. The captain of an airplane is responsible for the wellbeing of a multimillion dollar investment as well as the souls of a couple hundred human beings who are depending on that captain to get them where they are going safe and sound.
The more I think about this matter, the less respect I have for this agent.