3. Morpheus' Glasses (The Matrix)
At one point during sci-fi gamechanger The Matrix, Neo and Morpheus have a conversation inside "The Construct" - an empty white room used to upload virtual objects or run training simulations.
As the scene begins, the camera zooms slowly towards Morpheus, who's sporting a pair of matte grey glasses (see above). But then - literal seconds later - his glasses have changed to a shiny, black, reflective surface.
What just happened?
As you probably guessed by now, this isn't just an overlooked error - the glasses were switched on purpose.
For that first zoom shot, matte glasses were required so the camera wouldn't be spotted in the reflection of the glass, but for all subsequent shots of Morpheus, this wasn't an issue - so he was able to sport his shiny specs.