Other mistake: When Polly notices the reflection of Joe's airplane marking on the water, the code "hllod" gives "Polly." That's impossible. To get "polly" from "hllod," a person would have to rotate the word 180 degrees, not view it as a mirror reflection.
Sky Captain and the World of Tomorrow (2004)
1 other mistake - chronological order
Continuity mistake: When Joseph and Polly enter the Ark, we see the door close behind them, the countdown coming to zero. The Mysterious Woman, at the time, is out cold, or at least a dozen meters behind them. Yet, she finds her way onboard the Ark somehow.
Trivia: When Joe is going to shoot the bomb on the robot's legs, you can see King Kong climbing on the Empire State building in the background. (00:14:15)
Question: When the Hindenburg III docks with the Empire State Building, the newspaper shows early October 1939. Is there any clue as to what went differently in history concerning WWII?
Answer: None.
Rlvlk