When Tonetti and Guy are tied together after the night in the hotel room, they make a number of moves where they try to go in opposite directions, but are unable to because they are tied together. When the doorbell rings a final time Tonetti goes to answer the door and Guy goes to comfort Mimi, they are no longer tied together.
When Hortense first meets Tonetti, she is wearing a black cape. When she goes back upstairs to warn Mimi that she might have the wrong man in her room, she doesn't have the cape on. Then when she returns downstairs and talks to Egbert, she's wearing the cape again.
Whilst sitting at the night-club table Guy Holden is playing with a hand puppet which he proceeds to remove. The next shot has the puppet on the table and Guy now has his elbow on the table with his fingers against his head. The following shot has his arm stretched across the table.
Guy Holden, Mimi Glossop and Rodolfo Tonetti are eating grapefruit at breakfast when Egbert Fitzgerald and Aunt Hortense enter the room. In the next shot Guy has his elbow on the table with his hand on his head, which immediately changes back to Guy eating his grapefruit as before.
when at Brightbourne awaiting Mimi Glossop, Edward Evered Horton has a glass on the table in front of him. put there by Eric Blore. In the long shot, looking at Mimi's car, the glass disappears. The next short is a closeup and the glass is back on the table. Then when he gets up to approach Mimi, the glass has disappeared yet again.
During the part of the film supposed to take place just outside of London, the car chase between Mimi and Guy occurs with them driving on the right side of the road. He passes her on the left at one point.
During Guy's conversation with Mimi's aunt, in a seaside hotel in England, a large plant from the cactus family is reflected in silhouette outside the window, making it apparent that the filming was not done on location.
When Hortense and Mimi consult with Egbert in his law office, Hortense says Mimi has been married two years. The waiter (Eric Blore) says he met "Professor Brown" (Mimi's husband incognito) and his "wife" 3 1/2 years ago.
If Guy Holden is famous enough to be recognized by the French proprietor, why does Mimi not recognise the name? She mentions it when she first sees him at Brightbourne so she apparently knows his name.
During the "Continental" sequence Rodolfo Tonetti is shown playing a concertina and singing along. Though he moves the concertina in and out, and you can hear the music, his fingers never move on the keys.