Visible crew/equipment: During the flashmob, there are people walking toward the camera while dancing on the street. The shadow of the steadycam filming the scene is left of screen.
Continuity mistake: During the "Good Afternoon" number, Ferrell and Reynolds are standing in front of horses. They're fairly close to the two. The scene changes and the horses are further away.
Revealing mistake: Driving home from meeting Gigi, there is an image on the windshield of a blue handicapped parking permit/placard that is supposed to be hung on the rearview mirror, but there is no placard hanging - the permit's image is superimposed on the windshield. The image even briefly appears and reappears. (00:34:05)
Deliberate mistake: Elizabeth will not be able to save Mateo from falling backwards into the fire pit by grabbing his hand or pulling him back after his whole body is suspended over the edge. (01:13:47)
Continuity mistake: When the waiter puts Lily's "Cleopatra Special" plate in front of her, the long, white, curved ingredients (bean sprouts?) stick upward across her plate, but none are visible or sticking out in alternating views of her plate. (00:08:30)
Factual error: Josephine walks away from her father King Louie 14th, after he tells her she has to marry the young Duke Lintillac for his money. When you look at back of Josephine, you can see a zipper in her skirt. King Louie 14th was King from 1643 until his death in 1715. The first zipper was invented was in 1851. The zipper being used as we know it present day was invented in the early 1890s by Whitcomb L. Judson. (00:55:57)
Deliberate mistake: While roasting marshmallows, Henry's marshmallow caught on fire with the flame shooting about 6", then a foot+ high. A marshmallow subjected to such intense heat/flame for many seconds would not be stuck to the stick and stay stuck with repeated forceful flicking or "whipping" of the stick like Henry did. When the marshmallow finally flew off the stick and landed on a camper's head (higher than would be expected), it would be small/hard/charred, not large and still soft/white in the middle. (00:35:03)