Revealing mistake: Just before Hoffman knocks Jill out, there is no blood on her head or the table. As he grabs her head blood appears on her head just before he smashes it on to the table. (01:14:40)
Revealing mistake: When Travolta is fighting the Asian gangsters in the alley, he disarms one of the thugs by taking apart his opponent's gun. You can see that the Beretta pistol is partly disassembled before Travolta even touches it. (00:28:40)
Revealing mistake: In Frank and Sarah's first conversation her headset is on mute, shown by the fact it's blinking red. (00:02:25)
Revealing mistake: When Salt sits on the helicopter there are two of the same cuts with Salt looking through the heli's window with yawning guy in the background. Cuts split by the view of Washington DC.
Revealing mistake: Throughout the phonecall between Killer and Lucy, the call duration on the iPhone stays the same at 00:03. (00:37:00)
Revealing mistake: At the end of the film when the two Detectives are checking the sewer for the missing button. As the male Detective is lifting the sewer, the inner sewer lid paint peels back, exposing a white color of the sewer lid. Which makes you realize the sewer is likely made of a light wood or plastic (making it easier for actors to lift lid). It is obvious the "Props Crew" didn't do a good job in painting the sewer. It is made more obvious when the female Detective tries to hide the peeling paint by very quickly sliding her hand over the exact spot its peeling. Then in the next shot the male Detective does the same, but in the corner.