Revealing mistake: When Anna's looking at her reflection in the mirror she starts rubbing her face vigorously. Look at her right cheek and you'll it's red before she rubs, result of multiple takes.
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: 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: When serving on the bridge, there are multiple shots where skid marks from previous takes are visible. (00:44:20)
Revealing mistake: After Eddie's big dive, as he resurfaces there is a reflection of the water that can be seen above the waterline (on the camera lens).
Revealing mistake: When the cannibal throws Porter's body on the table you can plainly see its a rubber body. Especially when he cuts off the head.
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: 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).