Unfortunately not so. The legal whores in the Federal Government have signed “treaties & agreements” with foreign governments to enforce their laws against US citizens. Remember the guitar wood case?
Best bet is for him to lawyer up and not agree to make any statements (remember one misstatement is the normal way they get you for lying to the FBI or whatever and not any crime ... remember Dennis Hastert).
I remember the Gibson Guitar company Fiasco all too well...confiscations and all...yes