Revealing mistake: During the opening musical number, right before Gary joins the large group of people for the dance, he accidentally kicks Walter out of frame. Watch closely though. His foot comes nowhere near Walter when he supposedly "kicks" him.
Revealing mistake: When E.B. Is drumming along to Dynamite at the "Hoff Knows Talent" audition there is an audible bass drum beat but via several overhead shots you can see that E.B.'s feet do not reach either the bass drum or hi-hat pedals.
Revealing mistake: When Tigress is hatching a plan to escape Gongmen Tower after they have been trapped, she looks out over the wall. But take a close look at the archers: they all move in perfect sync, indicating the same animation models were used for all of them.
Revealing mistake: When the car Paul is driving spins out of control and flips, the roll bar is visible through the back window.
Revealing mistake: When Gryffin first hears the animals talk to him, he runs home and at one point takes a bath. If you look at the bubbles, they move in a solid mass when he shifts around in the tub indicating they are not only fake but not real bubbles.
Revealing mistake: When Mater and Holley are talking in the corridor, Mater's reflection is cast on the wall, but Holley's reflection isn't. (00:29:55)
Revealing mistake: When driving to the airport, you can see the reflection of street lights go over the front window, but the street lights out the back window never moves. (00:11:10)
Revealing mistake: Despite her claiming to be topless you can see what looks like a tube top on Kristen Wiig during her attempts to get the state cop to notice her.
Suggested correction: No, she's not wearing a tube-top. Looked up the scene on online. She has her hands covering her nipples, and her passenger Helen has her arm up in a gesturing manner partially covering her breasts, but there's absolutely no tube-top in sight. (I think you may be seeing part of Helen or Wiig's arm and think it's part of a tube-top).
Revealing mistake: When Umi is first descending the stairs in her house, her left hand clips through the left railing.
Revealing mistake: While Lynn is driving, the scenery outside the driver's side window goes white a few times and, other times, with intermittent specks of green tree leaves/shrubs. The white-outs are too low to be representing the sky. For a period of time, the lower third or so of her side window is a horizontal white bar. (00:02:20 - 00:03:38)
Revealing mistake: Near the end of the film when Jamie is 'talking on her phone' in the bathroom you can see in the mirror that she hasn't actually answered it.
Revealing mistake: When the LG billboard changes to the blue moon ad, the LG billboard is still visible on a reflection on the glass on the front of the MTV studios building.
Revealing mistake: When Johnny English tackles the Queen at the end of the film, you can see knee pads worn by the stunt double under her tights.
Revealing mistake: In the scene when they are travelling in the RV, the tea in the glass is perfectly still, even when the RV is obviously in motion. The tea should be jiggling in the glass.
Revealing mistake: As the guy is being pinned down by the giant hooks you can see for over a minute he can simply escape and slip his hands out. (00:52:30 - 00:53:30)
Revealing mistake: Locked out of the house, Katie has to wander around naked. Or rather, in her skin-colored tight fitting underwear. (00:16:22)