Revealing mistake: When Blake and Gordon watch Bane on TV during Gotham's siege, a grey (sometimes white) square is reflected on Gordon's glasses. It's either a lighting screen or the proof that the TV is turned off and the image on it is added on post-production.
Revealing mistake: When Cross and Kane are investigating the crime scene at the Asian woman's house, there are numerous candles burning in the woman's bedroom. The woman lit these candles at night, and Cross and Kane are conducting the investigation in daylight, which means all of the candles should have been burning for numerous hours. However, all of the candles are brand new and from the shape of them you can see they haven't been burning for more than a few minutes at most.
Revealing mistake: When Curtis or Catherine are driving while it is snowing (e.g, on their way to the Christmas party), there is relatively heavy snow going horizontally past the side windows but there is no indication that "snow" is falling on the windshield. Wipers can't be heard (like one would expect driving in these conditions) and there is no dimming of light inside to suggest the heavy snow is blocking some light. Also, the way the snow is accumulating around the side windows is not typical. (00:33:04)
Revealing mistake: IChat is used to make a second call to Professor Jonas, only this time we can see Professor Jonas is online under "Bonjour". Without too much detail this would mean that Professor Jonas is in the same house (on the same LAN) as Ellison. (01:31:55)
Revealing mistake: When The Deputy Charley Rakes goes to Cricket's house and attacks Jack, you see Charley throw Jack down the steps outside the house. If you look closely, you can see he lands on something really soft and spongy like a mattress which is hidden under the foliage on the ground to break his fall. When Charley walks down the steps towards Jack, you see him walk on it, which again looks really soft and spongy.
Revealing mistake: Ewan asks Mark to look at the newspaper article about the graduate who was killed. Other than the leading paragraph written in bold text, and the word 'tragedy', the other words relate to an article about the affects of global warming on great white sharks. The text is also duplicated three times.
Revealing mistake: When the truck starts rolling back you can see tyre tracks on the grass from previous takes. (00:46:35)
Revealing mistake: When Luke is signing the receipt for his new clothes, the amount on the CC receipt is less than $10.00. (00:40:16)
Revealing mistake: In the car chase, the stunt ramps on the ground so that both cars can easily race over the curbs instead of destroying their wheels. (01:20:20)
Revealing mistake: When Niles York first appears on camera beside the plane bearing his name, most won't notice, but you can see the pilot's hatch open, revealing that it is not a passenger jet, but a fighter plane. You can also see the air intakes on the wing, further evidence that this is not a passenger or private jet. (00:02:11 - 00:22:18)