Plot hole: At the end of the film Mardukas reveals that he has been wearing a body belt packed with cash - "in the neighbourhood of three hundred thousand dollars" - ever since Jack detained him in New York. Are we to assume that Jack Walsh, an experienced, hard-bitten ex-police officer, now a bounty hunter who routinely chases down violent and armed bail absconders who would kill him without a second thought, didn't even perform a perfunctory search of Mardukas when he detained him? This man used to work for the Mafia! What if he was carrying a weapon? A body belt with three hundred one thousand dollar bills in it would be uncovered by even the most casual pat down.
Plot hole: Andy is suspected of having killed Eddie Caputo, because he was at the scene when Eddie's house blew up and Eddie was killed. But there are glaring things that go unquestioned: None of the cops seem to think it's strange that a six-year-old kid would travel by himself so far to some random house in order to blow it up. The South Side neighborhood where Eddie lives is halfway across the city from Andy's apartment. How did Andy know where Eddie lived? How do the cops think he even knew Eddie at all? None of them address this most puzzling problem.
Revealing mistake: Any time when the two girls are in hell's corridors and running around, you see these corridors as stone walls, yet whenever they back up against one of these walls, you can clearly see they are merely rubber sheeting overlayed on a framework as the rubber sheeting bends and contracts very clearly.
Revealing mistake: As Reg fights with one of the baddies with the chainsaws, as the baddie take a swing with the chainsaw he misses and cuts into the wooden door. You can clearly see that a vertical cut has already been made in the wood though, to help the chainsaw get in and cut. (01:17:55)Hamster