Factual error: When Ewan McGregor's young wife is hanging clothes in her backyard, a small digital satellite dish is visible on the rooftop of one of the houses in the background. This isn't something that should seem out of ordinary, except for the fact that the events in the scene were supposed to be taking place during the Korean War. These dishes weren't commonly seen on rooftops until the mid to late 90s.
Continuity mistake: At the dinner table when Josephine tells about her article about Morocco Will's mother says "We have to pick up a copy", Will is holding a fork and his other hand is under the table. When it cuts the way he holds the fork change and his other hand is resting on the table.
Continuity mistake: As Will sleeps beside his unconscious father in the hospital, some papers are visible on his lap. In the next shot, he wakes to tend to his suddenly conscious father, and the papers disappear. No sound suggests they fell to the floor, Will makes no movements to account for them being on his lap, and in later shots, they are missing from the scene altogether.
Continuity mistake: When Edward and Karl the giant are leaving Ed's hometown, Edward hands over his backpack to Karl as he's taking a different path. In one shot Edward is Ewan McGregor, but in the next (when he's shot from the back) he is obviously played by a child. It's probably to make Matthew McGrory look big without special effects.
Continuity mistake: When Edward meets Karl after leaving Specter he walks out of the forest to the road on leaves. Even the shot looking down from Karl's point of view shows leaves all the way to the road. When the camera cuts to show down the road as they walk, only grass can be seen from the road to the edge of the screen.
Factual error: As Jenny Hill is signing over the deed of her land and house to Edward, you can see that the recording location (Volume, Page) is filled in. Also, the County Clerk's seal has been applied at the bottom of the document. In truth, this is the last step. The County Clerk will never see this document until all signatures have been gathered, and only at that time will the recording location be known.
Continuity mistake: When Edward is having his speech and says "To catch an uncatchable woman is to offer her a wedding ring." he is holding a glass. When Sandra approaches him, at first we see from behind Edward that he is holding his glass down. When it cuts to them about to hug, he has his glass by her shoulders and when it cuts again the glass is by her waist.
Continuity mistake: Around the table when Norther says "At night when the wind goes through the trees, you could swear there was a symphony playing just for you." Edward has a fork in his hand. At first there is nothing on the fork, but when young Jenny takes off with his shoes suddenly some pie has appeared on the fork.
Other mistake: When Will's mother steps into the bathtub where his father is already lying in, the camera switches between both persons and the water level (in relation to the bathtub edge) on each person's side is on a different height. Yet when both persons are shown, we can see that the bathtub edge is fully horizontal, so the water level should be the same on both sides.