Factual error: A 1955 Chevrolet is parked in front of Lily Tomlin's 1955 Dodge. Its license plate reads "528 GPR." California license plates did not begin to use combinations of three numbers followed by three letters until 1969. The "528 GPR" plate would have been issued circa 1975 and originally had yellow letters on a blue background. For the movie, the blue background was repainted black so the colors were appropriate for 1955. However, an actual 1955 plate would have three letters followed by three numbers.
Continuity mistake: The drawing of the church Kelly shows is different than the one she started to draw, even if she erased lines. The whole thing is shifted over to the right and both top lines go from angling towards the horizon to one being straight.
Other mistake: The town is Mt Barker. The red and blue ribbons on the sheep pen say Mt Baker.
Continuity mistake: When Joy is talking to the gentleman in the cowboy hat when in her room in Texas, the strings on his string tie change from on the left of his button to one string on each side of the button and back again.
Continuity mistake: Charlie's mock trial: the latina maid walks up the stairs, with Sebastian saying "OhmahGod, thank you." In the foreground, London is holding her goblet with her right hand, but in the next shot she has it in her left. (00:05:15)
Factual error: At the beginning of the movie, Jason Sudeikis pops out of a door wearing a Jurassic 5 T-shirt. Problem is, the artwork on it is from the cover of Feedback, their 2006 album. The scene, as the introductory caption says, is supposed to happen in 2002. (00:00:55)
Factual error: The producers took a lot of pride in using period-accurate furniture and clothing. But the family's house and furniture aren't remotely accurate for their actual situation. The table, the chairs, the house with a sleeping loft - all those took technology and manpower that they didn't have, and we've already seen that they had nothing to trade either. And they have more furniture than could have fit in that wagon.
Continuity mistake: SPOILER: The boy, Roger, finds a glove in a secret drawer in Mr. Holmes' room. The glove is lying perfectly flat in the drawer. It had supposedly been there for years unknown to Mr. Holmes. Later, in a flashback scene, it shows Dr. Watson putting the glove in the drawer. When he puts the glove in the secret drawer, it is not laid flat in the drawer - it has an obvious upward bend in the glove. Since the glove had been in the drawer, untouched, for years, it should have still had that upward bend.
Suggested correction: Although we are only shown Watson putting the glove in the drawer once there is no reason to suggest he may not have looked at it again before he left for good. More compellingly, Watson placed the glove in the drawer whilst the bureau was in place in Holmes' quarters in London, and it was not discovered until a quarter of a century later having been moved at some point to Holmes' house in Sussex. This journey could also easily have displaced the gloves position to some degree. The weight of papers contained in the drawer above may have also aided in flattening the glove out over the years.
Other mistake: In the break-in lab scene where the characters attempt to film their second resurrection, Zoe has her right hand on the electrical circuit breaker. After she throws the breaker and is electrocuted, Frank after unsuccessfully trying to revive her removes her wedding band, which shows clear burn marks on her ring finger of her left hand. (00:32:00)