"I am an American therefore I ain't responsible". Of course we don't know what security they had at Schiphol or their ethnicity. Could have been an inside job. How likely is it that anyone with half a brain would let a person get on an intercontinental flight without luggage, one way ticket and paid for in cash. With these three conditions I would have stopped anyone, even if their name was Smith or Jones.
Poland's central bank head calls story of Nazi train find a hoax (Reuters)
from the article: Israeli firm blasted for letting would-be plane bomber slip through