If their MOS was changed to Infantry as required by CIB regulations and they were in a Provisional Infantry unit I see no problem in them recieving the CIB.
I thought it was established in a different thread that Circular 269, dated 27 October 1943 did not require an infantryman's MOS to be eligible for the CIB?
3. Combat Infantry Badge.—Infantrymen, including officers, establish
eligibility to wear the Combat Infantryman Badge by—
Exemplary conduct in action against the enemy, or
By satisfactory performance of duty in action against the enemy in a major operation as determined and announced by the theater commander.
Furthermore, airmen of the regiment were awarded the BSM "for meritorious achievement while serving with friendly foreign forces engaged in an armed conflict against an opposing armed force from 7 Dec. 1941 - 10 May 1942."
Served is the key word...airmen served with the U.S. Army Infantry on Bataan.
Robert