Shoot 'Em Up (2007) - 6 mistakes

Deliberate "mistake": After Mr. Smith terminates the plethora of skydiving shooters, they all end up in an area the size of a basketball court, despite having markedly dissimilar velocities and trajectories created by the order in which they were shot.

Deliberate "mistake": Smith picks up the baby's mother to run away from Hertz after he finds out the gun won't shoot because of the finger prints reader. On the way to the stairs, she gets a bullet in her forehead. But Hertz is shooting from behind her, so the shot should be in the back of her head.

Continuity: In the diner at the end of the movie a man is slurping the last of a milkshake from the bottom of a glass. When the glass is shot it is almost full.

Plot hole: During the robbery at the end of the film, one of the wannabe badguys extends his left middle digit towards Mr. Smith, who then shoots it off. Since the gunsel's torso was directly behind the extended finger, the bullet, unless it was deflected by the upraised phalange, should have ended its journey somewhere around his left lung.

Continuity: During the love scene between Smith and Donna, when the killers first come in the door, Smith's pants keep changing from being down (while he is having sex with Donna) to up around his waist like normal as he rolls off of the bed.

Continuity: At the beginning of the film, Smith escapes with the baby on a bus. He takes off his sock to cover the baby's head. Cut to a shot of him pulling the sock over the baby's head, then the camera angle changes to a close-up of the baby being held by Smith with the sock on his head; cut back to the original camera angle and he's still pulling the sock on the baby's head.