Marin says the following within a 2-minute span: "I am almost 30 years old", "Dad is marrying someone who is only two years older than I am", "Dad is marrying a 33 year old". These statements cannot all be true.
When Harry and Erica are arguing outside the restaurant after Erica sees Harry with a young blonde woman her cell phone is in her hand in the shots where the camera is behind her, and not in her hand in the shots where the camera is behind Harry. Every time the camera switches she's either holding, on not holding, her cell phone.
When Harry and Marin arrive at the Beach house for the very first time, she can clearly be seen, from behind, wearing a small white thong under her white jeans. In the very next bedroom scene she has removed the jeans, and has suddenly changed into big knickers.
When Erica is on her Apple, sometimes the computer has cords connected in the back which is not possible on a Mac laptop of that vintage; later when she closes it, there are no cords or even connecting slots as is correct for a Mac laptop.
After the beginning credits, Harry says "So, darling, you are rich" and we can see his cigar is long.
Seconds later, he says "I'll like to meet your mother" and now the cigar is shorter. It's impossible he has smoked so much in a 2 or 3 seconds.
When Harry and Erica are chatting via laptop, we clearly see "VAIO" on the back of Harry's while he types in bed. That's a Sony PC running Windows. Harry's chat session shows the Apple Macintosh screen, which is what Erica is using.
When Erica and Zoe are listening to Marvin Gaye in the kitchen, Zoe has a glass in her right hand. While they are moving to the music Zoe wiggles her fingers, without the glass, in time with the song, however in the next reverse shot she has the glass in her hand again despite not having time to pick it up.
When Erica and Harry walk the beach, on the way back to house, in the shot just before the one when they stop in front of stairs, we can see that they've already passed the stairs, which are almost 20 yard behind them, in far distance. Suddenly, they are standing in front of them again.
When Harry goes to Erica's room to actually sleep with her, he gets in on the left side of the bed. However, in the morning, he is on the right side of the bed. As they lie in bed talking after awakening and the camera cuts back and forth between the characters, Erica's left hand is resting on her chest, then she is holding it above her chest, and then it is resting on her chest again.
The scene with Julain and Erica in the kitchen starts with Erica's hand pouring water out of a teapot. When we cut fully to her, Erica holds the pot over what looks like a towel on the counter. When we cut to her again a moment later, the towel is gone and the teapot is on the stove, its spout pointed toward the wall.
While Harry and Erica cyber-chat after their break-up, Harry keyboard is well-lighted as he is typing. A few shots later, we see Harry's finger against a dark background, and his keyboard is lighted by a single light.
At the second day in the Hamptons, when Erica, Harry, and Merin are shopping for groceries, Erica stands before a counter that has display containing copies of: "Food & Wine" on it, the display magically disappears/reappears between shots.
When Harry starts hanging up his coat in the restaurant in Paris he is wearing a big blue scarf. The camera cuts to Erica, then back to Harry as he is just finishing hanging up his coat, but the scarf has disappeared.
When Erica's sister picks up Dr. Mercer (Keanu Reeves) at the fruit market and brings him home as a surprise, Erica is setting the table for dinner. Erica had three place settings on the table already when dinner was going to be just her and her sister.
When Harry collapses the first time (at Erica's, while goofing around with her daughter) Marin calls the ambulance. We see her in the background, turned away from the camera, dialing, then turning around. Next time it cuts back to that very shot, she turns around again.
When Harry and Erica are walking along the beach, a house (presumably hers) can be seen in the background a few hundred feet behind them. After a couple of close-ups, they are shown in the next long shot as being considerably closer to this house, even though they've been walking away from it the whole time.
When Harry is getting wheeled out of the hospital, the camera turns on the other characters waiting for him in the parking lot. Although they were supposedly in the Hamptons, there is a palm tree and a California hill in the background.
When Julian and Erica are having dinner in the restaurant, Erica appears to be reading her lines from a teleprompter to the right of Julian's eyes. Done very well... but... she doesn't appear to be looking into his eyes... but... just to the right of his eyes (viewer's left).
After Erica and Harry's long walk on the beach, the sun is obviously low in the sky, and Harry asks if Erica would like to watch the sunset with him. She can't, because she has to get ready for her date with Julian. The date was set up for 7:00, so it must be no later than 6:30. It's the middle of the summer, so the sun shouldn't be setting for at least another two hours.