Continuity mistake: When the couple from Ohio is in the back of the squad car, the cop says that there is a hold up at a liquor store. When they get there, the store is clearly closed.
Continuity mistake: When Jack Lemmon and his wife Sandy Dennis are driving in their car on the way to the airport, you see a very different scene out of their rear window than you see when they show the outside of their car.
Continuity mistake: After just missing the first train, and then finding out that they may be able to take a taxi to catch it further down the line, George runs back into the terminal to find Gwen, who had gone to the ladies' room. As he's asking the cleaning woman where the ladies' room is, there is a woman visible in the background, putting on her coat and starting to walk away from the rest room. In the same shot, George runs to the ladies' room to retrieve Gwen and actually passes the woman as she is walking toward the camera. In the next shot, as George reaches the ladies' room door, the woman is back where she started from, and is again putting on her coat.
Continuity mistake: When George and his wife try to get back their room at the New York hotel with no success, they meet a man named Murray, who offers to take them to the Hotel Ashmount, two blocks away. When Murray agrees to show them where the hotel is, he says that it's only one block away.