Regis Toomey-Uncredited??

How could someone like Regis Toomey, who had by 1941 (the release date of the movie)been in the movies for at least 10 years and had co-starred in such movies as "G Men" and 'His Girl Friday" go uncredited in this movie?

"I told you a million times not to talk to me when I'm doing my lashes"!