Deliberate mistake: The whole premise of the movie is 'artistic license' so to speak; the protagonist signs himself up to the bone marrow donors register, called ADMO in his country (Italy). But he is still a minor, and that is strictly not allowed. Not even with a written consent of the parents as shown in the movie.
Continuity mistake: Emily Smith-Dungy just kicked her bags in the snow. Her neighbour and schoolmate Kat drives by and offers her a ride home. Emily after initially rejecting her help accepts it; the trophy switches hands from the first quick shot to the next. Her scarf is also positioned differently. (00:08:40)
Continuity mistake: Bera and Bea have multiple sequences where he complains about his roomie Ugo who lashed back at him after all the abuse he had to take from him. There's a plastic cup on the flush tank; in one of the scenes, in between others, the cup is suddenly in a different spot on the tank (more to the right) and the straw is tilted the opposite way than before. (01:11:00)
Continuity mistake: During dinner after the funeral Streep has a cigarette in her hand. The next shot her hands are together without a cigarette.
Factual error: Don Jon is set in a New Jersey town. A commercial for Hardee's/Carl Jr's restaurants comes on the TV during a family dinner. These restaurants are not in the New Jersey/New York area at all.
Visible crew/equipment: When Sonya is getting ready to get in the shower there is a shot from inside the bathroom of her in her bedroom, if you watch the closet closest to the bathroom door you can see the shadow of a nearby crew member cast on it, moving around. (01:04:27)
Continuity mistake: The protagonist is told about the budget cuts that will lead to the library shutting down. During the scene, the strap of his hat keeps going back and forth in front / behind his ear. (00:02:05)
Continuity mistake: When Keisha shows the father the painting she made, the father places it on the table over the color palette. Then after Keisha screams in the father's face, the magazine is gone. He sprays her with breath spray and replaces the painting over the color palette. (01:07:00)
Continuity mistake: The layout of the two slices of pizza on the tray and the position of Tyler's fork on his plate differ after Matt reaches the table. The slices of pizza are touching, then spread apart like a "V." Tyler's fork moves from being diagonally across his plate with tines facing him to being situated near the edge of the plate with tines facing Jessica. (00:13:19)
Continuity mistake: Notice how Julie pumps her shotgun twice within a few seconds in the lab without once firing.
Continuity mistake: In the first scene, Duncan is sitting to the right side (if we are looking at him) of the back seat of the station wagon. When they are taking the luggage out of the car, there are now bags piled up in the seat on the right side.
Suggested correction: Absolutely no telling how much time has passed between the two scenes. With them being on a road trip, they could have stopped for gas, food, bathroom breaks etc and moved the bags around at any time. Even Duncan could have just done it by himself mid-transit to make a little more room on the floor for his feet.