No, it was not FAKE ID....he really got it. When you get over there, it says you need a SSN but you sing a thing, where it allows you to get one.
He has a clean record, no criminal background and hes only 19years old, doesnt look mexican or illegal.
All he needs is his Drives License and thats it than?
If it is a real, valid Idaho DL, all he needs is that. They will see him as a normal passenger, nothing special.
He should leave his passport and any documentation about his status or country of birth/citizenship at home.
(He should not fly out of Buffalo, NY, by the way. Don't worry about the "Real ID benchmark" thing-- ID's from all 50 states are valid for the time being).