Feedback needed...

I am currently in the FBI pre employment process and just took my polygraph 6 days ago.  The result from the polygrapher (Federal Agent) whom administered the polygraph was that I passed. He also pointed out that he does hundreds of polygraphs a year and that he grades them very strictly. Presently, I just got a call today and got a heads up from a friend of mine in the FBI, that FBI headquarters said I failed my polygraph due to using countermeasures during control questions.  I am very pissed off and frustrated because I don't even know how to do any of these countermeasures.  Until today, I had no idea there ever was a way to use countermeasures during a polygraph. All I know is that I was extremely nervous through the entire process and I answered all the relevant questions fine.  If the agent who gave me the test said I passed, do you think I have a direct argument that I can take back to human resources?  Please help!  I just don't understand how the U.S government can wrongfully accuse me of something this absurd....

YOUR OPINIONS OR PROFESSIONAL ADVICE WOULD GREATLY BE APPRECIATED...  THANKS

Thanks for sharing some insight and your advice.

YES, I am definitely going to contest this and let them know that this system is flawed and I told nothing but the truth.  The sad part about this whole thing is that I answered all the relevant questions fine.  Both the director and the polygrapher here even said that they triple checked my results and I did fine. They can't understand how this can happen.  They want me to submit a request to retake my poly, but I'm still waiting on the official document to arrive so that I have a basis for my argument.  This has been so nerve racking for me and it continues to bother me everyday.  So many scenarios keep running through my head!  Sometimes I think that maybe I passed but they're just testing me to see how I will react to a situation like this.  Since the day of my very first interview, they have already used several different deceptive techniques to deter me from anticipating what was coming up next.  I know I'm just being skeptical on a lot of things, but this is one instance that I hope they're just testing me.  I just keep thinking that only because if I really wrongfully used countermeasures and was trying to beat the polygraph then the examiner would have detected it in the first place.  He told me himself that he grades these things extremely hard and that I passed it just fine.  Like I said, I really hope all this is just a test!!!  If this is, it would piss me off in the beginning, but it would also bring me piece of mind in the end just to know that I passed this stupid thing!