When the documents are blown over the ship, they are blown to one side, but in the next shot you can see a flag blowing to the opposite side.
When Josh Lucas dives into the water of the cove, it is almost perfectly still and glass-like. As they show Jean photographing him (in black and white) at the exact same time, the water is very choppy indicating there is a stiff wind blowing.
During the conversation about how Jean and Thomas met, Jean is alternately holding a glass and lighting a cigarette.
When Adeline dives into the water, she is diving away from Jean and towards the sun. Yet when the shot is on Jean, watching Adeline, the sun is behind Jean. In the next shot, the sun is clearly on Jeans left shoulder and as Thomas wakes and comes on deck and speaks to her, the sun is now on Jeans right shoulder.
When the tea kettle reaches boiling, we see steam escaping not only from the lid but also from the completely uncapped spout. And yet there is a whistling noise. Steam doesn't just whistle. It has to travel through a pressure release valve to make a sound. This kettle clearly did not have one.
The end credits misspell Strawbery Banke Museum as "Strawberry Bank Museum."
At 28 min. while playing pick-up sticks on the sailboat in the evening over wine the number of sticks and their positions continuously change with every angle and shot of the pile. It is clear it is not from the playing of the game as large amounts of sticks come and go in a short amount of time. Also the quantity of sticks in Adelines hands raise and lower frequently throughout the scene.
When John Hontvedt, the Norwegian husband, turns the tea mug over at the site of the murders, there is a modern factory silkscreen stamp on the bottom of the mug.
The oil lamps in the courtroom had incandescent mantles. In fact, the mantle was not invented and patented until 1885.
Smuttynose Island is in the state of Maine but the trial in the film took place in New Hampshire. The state line divides the Isles of Shoals.