No Donofrio...the so called “immigration investigation” if that’s what you think it was likely was based on the word of a liar who was trying to extend his stay in the United States. It would have been beneficial to his cause if Obama Sr, said Jr was born in the US, by going along with the Dunham family story, than state he was born in Kenya. The immigration official does not state how he derived that Obama was born in the US, but the dubious info very likely came from Obama Sr, during the interview. Your conclusion has a big hole in it.
Donofrio
It is my opinion that a proper FOIA request for passport issue cards (or copies thereof) will establish that Stanley Ann Dunham did not have a passport prior to August 4, 1961. Such a request must be SPECIFICALLY designed to eliminate all wiggle room. I suggest the following wording: .... But we do know according to the liar Sr (did he tell the truth that time?) that SADO was in the Philippines prior to 1965. And according to the State Department, any passport records that Stanley Ann Dunham Obama had prior to 1965 was destroyed via General Services Administration (GSA) directive. The GSA have disputed that claim that was made by the Obama State Department.
One critical exchange is dated August 21, 1967, from Sam
Benson, an officer at the Southwest Immigration and Naturalization Service office in San Pedro, Calif. Benson’s query stated, “There is nothing in the file to document the status of the spouse’s son. Please inquire into his citizenship and residence status and determine whether or not he is the applicant’s child within the meaning of Section 101(b)(1)(B) of the Act, who may suffer exceptional hardship within the meaning of Section 212(a).” 
A response to Benson’s inquiry came from one “W.L. Mix” of the central immigration office, who determined Obama was a U.S. citizen.
Mix replied: “Pursuant to inquiry from central office regarding the status of the applicants’ spouse’s child by a former marriage.”
“The person in question is a United States citizen by virtue of his birth in Honolulu, Hawaii, Aug. 4, 1961. He is living with the applicants’ spouse in Honolulu, Hawaii. He is considered the applicant’s step-child, within the meaning of Sec. 101(b)(1)(B), of the act, by virtue of the marriage of the applicant to the child’s mother on March 5, 1965.”
The files do not state how the office determined Obama was born in Honolulu.
THE DIVORCE DOCUMENT WAS THE SOURCE! NO BIRTH CERTIFICATE SIGHTED?
NO PROOF OF A PREVIOUS MARRIAGE WAS PROVIDED? BOTTOM LINE: THE DIVORCE FROM THE KENYAN AWARDED CUSTODY TO STANLEY ANN DUNHAM OF AN UNIDENTIFIED CHILD.