Factual error: The IOWA airman had a very wrong pronunciation of the town of Ottumwa. He pronounced the U as in TUBA, when in fact, it is pronounced as in TUMS. I checked with older residents, and they agree, it has always been pronounced the same.
Continuity mistake: In Morocco, when Lee, Capby, and Roberts take off, they still have their external fuel tanks under their wings, indicating they have not entered combat. As they are flying and do their mission, they have dropped their tanks. But after Lee says "let's head for home," you see one Mustang landing, external tanks and all.