Although I doubt that Doug Williams is voluntarily sharing any information about his purchasers with the government, there is always a chance that the FBI or someone else is sureptitiously observing everything that goes through his website.

Even if this is not the case, there is a chance that the FBI could find out about a purcahse of "How to Sting the Polygraph" during a background investigation.  I know for a fact that when you apply for employment with the FBI, you sign waivers granting the bureau access to all of your credit card information (obviously this did not happen in your case, because those disqualified by the polygraph never reach the background investigation).

With all of this being said, Doug Williams manual is a resource worth having.  If you want the pamphlet, there are ways it can be obtained without performing a transaction in your name.   Using a money order is one way.  Having a friend or relative with a different last name purchase it by credit card is another.  Also, you may wish to have it sent to someone else and have them remail it on to you.  

Lastly, I am curious about one thing.  Did the polygrapher himself accuse you of using countermeasures during the "test?"  Or, were you notified later by phone/mail?

Best,