From the hotel room window in Stockholm you can see that it is snowing all the time, but outside shots only show just some last remains of snow in the city, where there should be a nice layer of fresh snow.
The Lucia celebration is on the morning of the 13th of December, the Nobel prize ceremony is held on the 10th of December so the time-line is wrong.
The correct pronunciation of the surname of Alfred Nobel is no-BELL. It is variously pronounced as NO-ble and no-BELL throughout the movie, even some of the presumed Swedish language speakers pronounce it wrong.
Joan tells Nathanial that if he does anything to malign Joe's work, she will take him to court. First, any honest critique of an artist's work would be protected by the First Amendment. Second, you cannot be sued for slandering the dead. Third, since Nathanial's allegations would be perfectly true, she would have no case.
The Nobel dinner always takes place in The Blue hall in Stockholm City hall, and this looks distinctly different from the room used here.
A shot from the bathroom in Grand Hotel in Stockholm shows an outlet of a type that is not used in Sweden.
When David addresses his sister's stomach, he says, "Hello, little man." When Joe talks to the gathered crowd, he refers to his grandchild as floating in HER mother's amniotic fluid. But it's quite possible they did not know the sex and were just guessing, supported by the fact that when she calls her parents to announce that she ha given birth, they ask, "What is it?"
Linnea is a professional photographer, yet she never adjusts the focus ring when snapping photos. Also, during the rehearsal, she is standing much to close to Joe to get any kind of usable photo.
When Joe and Joan are in the study in Connecticut, 1968, there's a view of the sea through the window. But the waves don't move at all during the shot.
An aerial shot of Stockholm shows a long, blue bus on a street. That type of bus was not yet in service in 1992.