On the dirigible, Rumford is seen wearing a hat when he opens a door to a cabin, but he is hatless when the point of view switches to show him entering the cabin.
Admiral Winfield, aboard the dirigible, is referred to as Chief of Naval Operaitons, but wears the stripes of a rear admiral. An unnamed admiral aboard a surface ship wears the stripes of a full admiral, the usual rank of CNO.
The telegram Bancroft sends to Saxby is addressed to him at the "Federal Bureau of Investigation". Saxby and Bancroft are members of the Secret Service, which is a part of the Treasury Department. They have nothing to do with the F.B.I., which is part of the Justice Department.
The police hand over the dead hobo's $50,000 and other evidence without requiring a receipt, a clear violation of police procedure involving the chain of custody.
The dirigible USS Mason is referred to repeatedly by that name, but the name painted on her envelope is Macon (the name of the real-life Navy dirigible lost at sea in 1935).
The crash sequence involves three different aircraft/props: two high wing monoplanes, one without struts (the sighting in) and one with struts (the drop), and a low wing monoplane (the actual crash).
The newspaper article about the testing of the new weapon misspells the word "capitals" (meaning governmental seats of countries) as "capitols."