Folks by the millions come into the United States all the time WITHOUT the assistance of the CIA. Why would this guy need the CIA? Was he not as educated and smart as your typical Mexican illegal?
Why would a good, middle class guy, a lieutenant in military intelligence in Germany, from a well-known Christian Democrat family, in no need of money, and absolutely no record of extremism, want to sneak over the border?
Obviously there’s no way of knowing, but Ockham’s Razor suggests that he was invited as a shared intelligence gesture. Especially when virtually everyone at Elohim City seems to have been a double agent working for some branch of US government. It’s even been suggested that the Pastor in charge of Elohim City was not really a simple Nazi Aryan cultist but yet another double agent. Else why was he friendly with such strange folks?