I could not make any connection to Callahan County, Texas and have concluded that the War Dept mistakenly used Callahan County, Texas as his home of record during 1946 when compiling casualty lists confusing it with Calliham, Texas.
Edward Haag Jr. born 17 August 1917 in Thrall, Williamson County, Texas to Clara Wilhelmina Sternberg (b. 1876 Washington County, Texas - d. 1948 San Antonio, Bexar County, Texas) Age 41 and Edward Haag (b. 1879 Comal County, Texas - d. 1944 San Antonio, Bexar County, Texas) Age 38.
1920 Census JP6 Williamson County, Texas age 2 living parents, two brothers and a sister. 1930 Census JP3 McMullen County, Texas age 12 living with parents, two brothers and a sister. 1935 living same house. 1940 Census JP3 McMullen County, Texas age 22 living with parents and brother. Registered for the draft at Tilden, McMullen County, Texas on 16 October 1940 while living and working a farm near Calliham, McMullen County, Texas and listed his father, Ed Haag Sr. of Calliham, as his next of kin contact. Edward Haag Jr. asn-18023866 a single white male born Texas in 1917 residing in McMullen County, Texas working as a truck driver with two years of high school education enlisted into the US Army Quartermaster Corps Philippine Dept as a private on 14 December 1940.
Corporal Edward Haag Jr. 18023866 Company B 505th Parachute Infantry Regiment 82nd Airborne Division.
I do not know who is responsible, the military probably since this was early in the war and casualty identities was their responsibility especially to the next of kin.