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.
The Next Three Days (2010)
1 revealing mistake
Directed by: Paul Haggis
Starring: Liam Neeson, Elizabeth Banks, Russell Crowe
Other mistake: Lara's hair is plain and pulled back in a pony tail when she first escapes. Within a short period of time, her hair becomes nicely styled but she would have needed a fair amount of time with a curling iron, hairspray, etc., for it to look so nice.
Damon Pennington: No prison in the world is airtight.
Question: Would the plan John used to help Laura escape really have worked? If not, then please explain why?
Answer: John's plan to help Laura escape would not have worked, because he would not have been able to plan ahead like he does in the movie. He would to know where Laura would be transported, and when and if she would be transported there. He would not have know any of that as the information is kept secret from the prisoners, and the public.
Even if he did find out Lara was in hospital, Lara would have been transferred to another hospital.
The movie attempts to cover this up by having him send fake diabetic results to the jail. This would not work because jails and prisons do not accept diabetic results from outside labs.