When a male train passenger tries to wedge a note between the door and door frame of Odette Mauclair's room; the note falls into the room and out of sight. But on the next cut when Londais escorts Odette to her door; the note is now seen wedged in between the door and the frame.
When Londais and Mauclair enter the cab after the trial; the insurance agent stands outside the front passenger window and starts to berate Londais. But on the next cut Londais in order to ignore him pulls down the rear passenger window shade which is the wrong one.
Istanbul is misspelled as "Istambul" on the train's destination board.
When the French paper Le Matin reports the trial result for Baron Von Kampf; the headline and first paragraph are in English however the rest of the column and also the other stories in the paper are in French.
On the train, Col. Jackson does not lock his compartment thus allowing Mauclair to enter and steal the jewels. This would not make any sense since Col.Jackson is a professional thief and would not make such an obvious security breach.