Section 301(a)(7) of the Immigration and Nationality Act of
June 27,1952,66 Stat. 163, 235, 8 U.S.c. §1401(b), Matter of S-F-and G-, 2 I & N Dec. 182 (B.I.A.) approved (Att'y
Gen. 1944)
This apparently is the rule. It might be changed now, but when he was born the age was 19.
HO I believe they are saying he WAS NOT born in Hawaii so that's part of it too along with his mom only being 18.