NSA.gov Site Defacement
praetorianprefect.com
praetorianprefect.com
Defacement of a public portion of the NSA's site is just going to land you in a world of hurt, even if you are in a far off country.
Or he could have just emailed them the document and called them to tell them the password.
This is a standard way to catch people who do this type of stuff. Once he sets foot on American soil, he would be arrested. You actually have to be pretty dense to fall for it. ~99% of employment at the CIA requires some form of security clearance, which in turn requires you to be a US citizen.
What you wrote is just a bit unlikely. If US can force a UK citizen and a "hacker" (NASA case) to be transported to US for the trial even after many appeals, why would it be a problem with Canada?
Also, I'm fairly certain you are incorrect about security clearances (at least for Confidential, Secret, and Top Secret). Even dual citizens have to shred their extra passport and renounce their additional citizenship. The FBI website mentions that for Top Secret, citizenship is verified through investigation: "For a Top Secret security clearance, the background investigation includes additional record checks which can verify citizenship...." [2] If you're working at an intelligence agency like the CIA, Top Secret is pretty much required.
[1] http://www.pcworld.com/article/173397/uks_high_court_rejects...
Otherwise I believe you are right in most cases. One would have to be rather naive to simply accept such an offer blindly.
This tells us nothing of whether the NSA is good at finding people on the internet, however. Was the email anonymous? Did he use a proxy?