Continuity mistake: When Erica and Harry are having a picnic at the beach, they go for a little walk and it starts raining. They hurry back into the house and, the first time they are seen in close shots, they're absolutely dry. A couple of seconds later, in other two different close ups, they appear to be soaking wet.
Continuity mistake: When Jack Nicholson and Diane Keaton are in the kitchen and Diane is making pancakes, she is talking to Jack and holding the milk. She pours some milk in the bowl and puts the cap back on while she is talking then the shot switches to Jack and back to Diane and she puts the cap back on the milk a second time.
Revealing mistake: In the scene where Harry and Erica are walking on the beach, Harry bends down and supposedly picks up a black rock to give to Erica. However, the viewer can see Harry take an object out from his left pocket and, while concealing it with his left hand, transfer it over to his right hand as he bends down and pretends to pick up the rock from the beach.
Continuity mistake: When Erica and Harry take their first walk on the beach, Erica reaches down to pick up a white stone. When the shot changes and Erica stands up straight again having picked up the stone, all the sand in front of them is dry. However, in the shot just prior to her picking up the stone, the sand is actually wet from the seawater.Richard Holmes
Continuity mistake: In the scene where Harry and Erica are walking on the beach. There is a dark grey house with a brick chimney in the background directly above and behind Harry's right shoulder. As they continue to walk, the house in the background continually moves farther away and closer in almost every different shot of them talking. In some shots you will see them far away from the house, then seconds later you see them very close to the house.
Continuity mistake: When Harry, Erica, and Marin are in the grocery store, the size of Harry's ice cream cone changes. In the first clip, he is eating the ice cream off the top of the cone. The next few scenes, ice cream appears at the top of the cone again in varying sizes.
Continuity mistake: When Keaton and Nicholson argue outside the restaurant and Keaton confesses she is in love with him, in certain closeups Keaton holds her head with both hands. When the camera cuts to Nicholson's face, you see her back and her arms are down. This happens twice during the scene.