Continuity mistake: When Arnold comes home after work, he always parks next to Kay's car in the driveway. As he does on the night Kay tells him they are going to the therapist's office. He is undecided about the trip and doesn't act to join her until after she leaves. Yet, when the taxi arrives to pick up Kay, there are no cars in the driveway.
Audio problem: In the scene where Tommy Lee Jones and Meryl Streep are going into the therapist's office for their first appointment, which is scheduled to be at 10:30 am, bells are chiming in the background that indicate the time is actually at the top of the hour.