|Myrna Loy and Jack Conway.|
Only ten directors have made two Best Picture nominees in the same year. These men, including Ernst Lubitsch, Michael Curtiz, Victor Fleming, John Ford, Alfred Hitchcock, Francis Ford Coppola, Herbert Ross, Steven Soderbergh, and Sam Wood (who did it twice), were all nominated for at least one Oscar. Some of them even won Oscars.
However, Jack Conway is the only director to direct two Best Picture nominees (Libeled Lady and A Tale of Two Cities from 1936) in the same year without EVER being nominated for an Oscar. Regardless of whether or not he deserved a nomination, that statistic might be the ultimate snub.
You can find more info on the ten directors here.