Revealing mistake: When Gerard Butler is driving to the warehouse to find Frank, the speedometer and the rev counter are on 0.
Suggested correction: I could not see Will's speedometer or tachometer (RPM gauge) during his drive to Frank's. What I did see (and believe you saw) was the patrol officer's instrument panel while he was parked along the road using radar. This was before he pulled out to chase Will's speeding SUV, so both gauges should have been on the far left (i.e, on "0"). [00:46:28].
Revealing mistake: When Will enters Knuckles' trailer, the inside front door is light-colored and has a diamond-shaped window. A little later, when Will is swinging the crowbar, the door behind him is dark-colored and - in a flash - the top of the diamond-shaped window spread out (forming almost the top half of a hexagon). [This happens very quickly, so you will probably need to watch several times (and on a large screen) to see the transformation.]. (00:42:03)
Revealing mistake: The blinds on the window near the TV are closed when Will first enters Knuckles' trailer. During their fight, the blinds appear to be either pulled up more than halfway or the center slats are overlapping. When Will goes back into the trailer after the fight outside, the blinds are halfway up. Although the fight in the trailer is fast, and they move around a lot, the objects in the room frequently vary, indicating use of a green screen. (00:42:06 - 00:44:37)
Revealing mistake: The objects outside of Knuckles' trailer when Will throws him out the front door change. Knuckles landed next to boards (box springs?) and a mattress, but when Will got behind Knuckles, there was a box and a garbage bag where the mattress was then the box and garbage bag disappear. (00:43:43)
Revealing mistake: When Will got to Knuckles' and was walking past the driver's side window of his car after getting a crowbar out of his trunk, the instrument panel had one circle to represent the speedometer (similar to a clock) but no dial. (00:40:00)
