On the bomb run to Berlin, after the B-17s drop their load they remained on level flight. When a B-17 drops it's load normally it pops up with the weight loss.
The Red Tails are shown to transition directly from the P-40 to the P-51D in the movie. In reality they first transitioned to the P-39, then the P-47, the P-51B/C, and lastly the P-51D.
Andrew 'Smokey' Salem: When you get upset, when you get mad, you turn red, right? When you get envoius, or sick, you turn green. When you become cowardly, you turn yellow; and ya'll got the nerve to call us colored?
Joe 'Lightning' Little: Nothing's difficult. Everything's a challenge. Through adversity to the stars. From the last plane to the last bullet to the last minute to the last man - we fight. WE fight! We FIGHT!