When Kay is upset and walks through the rain, her hair is wet and a mess. When she walks into the bar she runs her hand through it quickly, and by the time she sits down (a matter of seconds) her hair is dry and all in place.
In almost every exterior scene of Kay and Arnold's house we see a Buick sedan and a Subaru station wagon parked in the driveway in front of the garage. However, when the taxi picks up Kay to take her to the airport and drops Arnold and Kay back from the airport the cars are not in the driveway. It was suggested that since they were going out of town they might have moved the cars into the garage, but when Kay leaves it is unknown, even to Arnold himself, if he will accompany her.
Early in the movie, when Kay gives the leaflet to Arnold at the breakfast table, camera angle 1 shows him folding the paper and placing it on the table. Then it cuts to camera angle 2, and Arnold is folding the paper again.