Corrected entry: When the helicopter crashes into Skyfall, depending on the angle the undercarriage is down when the helicopter tilts forward, then up from behind, then down again from the front.
Corrected entry: Before the final battle at Skyfall, M, Kincade and Bond have laid out a few guns on a table. These are the only available firearms since M distressingly asks, "And is this is all we got?" Among them is Bond's pistol, only usable by him because of the fail-safe hand-print sensor. However, we can see M firing with what appears to be Bond's pistol in the ensuing battle scenes.
Corrected entry: The caterpillar digger on the train carriage would have been too large to fit through the tunnels later on in the train fight. Lucky it was decoupled or there would have been a serious accident...
Corrected entry: In the Commons Committee scene, when the CO2 extinguishers are shot, they slowly release their contents over a long period of time, giving a significant 'smokescreen'. In fact, a shot which was able to penetrate the cylinder would cause a very quick release of gas, and the 'smokescreen' effect would be fairly limited.
Corrected entry: In the train scene the carriages are de-coupled by shooting out a chain. Carriages are never held together by a chain, but rather by a special hook (which can be seen in this shot). Even if they were just held by a chain, the chain would not be destroyed by a bullet shot.
Corrected entry: The glass on the windows on skyscrapers like the one in the skyscraper/assassin scene is specially made for high altitude building and is usually very thick (4-6 cm thick, as seen by the section the sniper removes), this means that during the subsequent fight scene it would have been impossible to break that window just by bumping into it.
Corrected entry: In the opening car-driving scenes, Moneypenny is wearing her seatbelt, then she isn't, then she is.
Corrected entry: At the end of the film, Bond is standing on the roof. The time seen on Big Ben is 5.55, and there's loads of traffic in the background as well. He returns downstairs with Moneypenny and Tanner appears from M's office saying "morning 007". If it was morning in the winter months (Scotland having frozen lakes) it would be dark and not daylight that early.