At about the 0:49 minute mark as Anne holds a card that was with flowers she received, the hand shown has dark nail polish, but Kay Francis has on light or clear polish.
The hotel operator tells the man in room 543 that there's a raid in progress. But the man emerges from room 414.
In the restaurant of the Hotel Metropole in Havana, the supposedly Cuban waiters (one of whom is referred to as "Pedro") speak to each other in Italian rather than Spanish. The actors playing these roles, George Humbert and Gino Corrado, were both born in Florence, Italy.