When Kenney selects the cleaver as his weapon of vengeance from the basement sink, it is still in the sink later, even though he is lying halfway down the basement steps.
Ray's feet change position after Scudder hit Albert with a stun gun and when he shot Albert on the head.
During the chase, the left tail light of the truck is shot. In a subsequent scene, it is repaired.
When Scudder and Landau spoke in the Landau's house and looking at Mrs. Landau, her hair changes among three shots.
The computer keyboard was on the right side of the table when Albert fell. Later the keyboard was under his body when he tried to stand up and shot by Scudder.
In fight near the end of the film Scudder fires a pistol 5 times with the barrel only an inch from his right ear, but appears unaffected by the noise or firing action. Both the noise (which would likely be greater than 140db) and the firing action are close enough to cause permanent damage.
Green-Wood Cemetery is locked and patrolled by security at night; they could not just drive in at 10:30pm for a confrontation with the kidnappers.
At the beginning of the movie Scudder is firing an M1911 pattern pistol at the fleeing robber. There is no similar weapon on the approved carry list for a regular (carrying a badge and not undercover) officer of the NYPD.
In the opening scene, it says 1991. When Liam Neeson walks into the bar and opens the newspaper, it says on the back of the newspaper that Nolan Ryan pitched his fifth no-hitter. That happened in 1981, not 1991.
During the fight in the basement, the table starts to break before they fully hit it, making it obvious that the table wasn't "real", also Scudder picks up the table leg and it is obviously cut straight across rather then jagged like a break would be.
(at around 6 mins) The year jumps from 1991 to 1999. As soon as the year changes to 1999 Scudder is sitting in the diner reading the Daily News. However, the back page of the newspaper is a story about a Seton Hall Pirates basketball game from 1991 (the front page looks to be era correct as there is a story about Y2K).
They keep referring to Laura Birn's character as Leila Andresen and in the credits she is listed as Leila Alvarez.
(at around 56 mins) While set in 1999, when Scudder clears moisture off a windows in the old house you can see a modern time (built after 2010) white car parked below the train bridge.
Matt keeps calling TJ "P. Diddy." But Sean Combs wouldn't use that name until 2001. The movie is set pre-Y2K.
A few minutes before the end, TJ is talking to Scudder from his cell phone. He tells Scudder that the Brooklyn house where the bad guys live is near the intersection of Church Avenue and 53rd Street, and Scudder replies "That's in Boro Park". Wrong. A section of 53rd Street does pass through Boro Park, but 53rd Street doesn't intersect Church Avenue anywhere. Church Avenue actually intersects East 53rd Street in the East Flatbush area, several miles from Boro Park.
Near the end, in Albert's and Ray's house, Matt secures Albert to a pipe and sits him on the radiator. Albert manages to free himself...but how? All the viewer sees is Albert using his left foot to push a drawer open, a drawer that--as we saw earlier--contains handcuffs.
The boy in the bodega asks, 'Como esta la leche?', which is 'how is the milk', when he should have asked 'donde esta...', because the proprietor says, in English, "you know where it is!"
Laura Birn's character name wrongly written in the credits as Leila Alvarez, where in fact on several occasions she is referred to as Leila Andressen by various characters.