After the fight with Charlie, Jack's leather jacket is wet from the rain. When he walks out of the shack a couple of minutes later, it's dry.
When the coin is originally placed into the parking meter, the limit on the meter is marked as 30 minutes.
Later when the police find the meter it reads 10 hour time limit.
When Jack then goes back to the area in the car park where Barr set up to fire the meter once again reads 30 minute time limit.
During the car chase scene with the police, the inspection sticker can be seen on Reacher's car. Initially it states July 2012, but then it changes to September 2012.
When Jack saves Helen, he enters the place with wet hair, some hair on his forehead. When the scene changes (after small talk with Helen, when Jack meets The Zec), Jack's forehead is clear.
When Jack meets Martin Cash for the first time: During the entire scene, Jack has a different hair cut compared to the rest of the movie.
When Jack Reacher pulls out the Camaro's registration, it erroneously reads "State of Pennsylvania." Like three other states (KY, MA, and VA), Pennsylvania official designates itself as a "Commonwealth" not a "State."
Early in the film, Helen tells Jack that their conversation is attorney-client privileged. No competent attorney would make that claim, as discussions with non-party witnesses are not at all privileged.
At the range, Reacher and Cash are looking at the target after Reacher puts 3 rounds through the "X" ring, The holes are perfectly round and cleanly cut. A pointed rifle bullet leaves a ragged hole and would never leave a perfectly round hole through a paper target.
When Jack is answering Prosecutor Rodin about what he knows, he says "there is a bus station 3 miles away and I can walk there in 24 minutes." Even the fastest walkers can't cover 3 miles in 24 minutes. That pace is a run or jog at best.
When Jack reverses the car into the quarry the engine tone suggests several gear changes while the car clearly only has one reverse gear.
Though it may seem anachronistic for Barr/the sniper to use the M-14/M-21/Springfield M1A as his weapon of choice, it's origins trace back to the M-1 Garand from WW II, the weapon, in one form or another continued to be used by units of the US Army and Marine Corps during the wars in Afghanistan and Iraq as a sniper/designated marksman weapon.
Reacher's first clue about Barr's innocence is when he sees that an experienced sniper would have shot from the bridge instead of the garage. It might be expected that someone who could out-shoot Barr would have carried out the shooting from the bridge to emphasize Barr's guilt. But the plot clearly shows that it was necessary to fire from the garage position to be able to hit Oline, several other victims, and the liquid backstop which is integral to the story.
The "highway bridge" the sniper should have used is the I-279 bridge. It is shown to have the sun behind it (west) in both the original shooting and the hypothetical discussions. This would mean it's evening (sun is low in the sky, during summertime) - not the morning, as indicated by the shooter's watch and the victims' stories.
Legal documents states parties as ONLINE ARCHER vs. the LEBENHAUER corporation instead of OLINE ARCHER in 2 separate scenes.
When Barr is shown shooting at Hinge Creek (intercut with Reacher firing a different rifle), and at various other points in the film, he obviously jerks the rifle in anticipation of the recoil-- something a trained ex-military sniper would never do.
When Jack calls Helen's from a payphone, Charlie answers and puts it on speaker. When Jack hangs up and calls again, Charlie keeps the phone to his ear for the "I'm not a hero" speech. However, when Jack finishes, Charlie, Helen and the Zec look as if they all could hear the conversation.
When James Barr is being interviewed in hospital, the latex 'scab' on his lip has clearly lifted away from his skin.
When Reacher is chased in the Chevelle, it has two different inspection dates on the windshield. One for 6/12 and another for 9/12.
During the opening credits, the sniper is heard to fire while the view through the scope shows the victim instantly dropping. At the range shown, there would be a visible delay between the sound the sniper hears and the target being struck (assuming the sniper could hold the rifle steady enough to watch).
In the opening scene, it shows the shooter on I-279 South heading into downtown Pittsburgh. In the next shot, it shows him exiting the Ft. Pitt tunnel, onto the Ft. Pitt bridge. The Ft. Pitt tunnel and bridge are on I-376, which enters downtown Pittsburgh from the west.
The antagonists kill Sandy in order to frame Reacher for her murder, however, at the time of the murder, Reacher was with Helen Rodin at her office. Even if he was arrested, he would have been released very quickly as soon as Helen confirmed his alibi.
Jack warns Helen about investigating Oline as "just saying her name could get her killed".
However, Helen has already run the plates of the car registered to the company which Reacher should have guessed would have alerted the bad guys that she was onto them.
However, Helen has already run the plates of the car registered to the company which Reacher should have guessed would have alerted the bad guys that she was onto them.
Reacher found suspicious that the police arrived too quickly after the street fight. But who called them? The bullies expected to beat up Reacher. So they were not also interested in alerting the cops. Nobody else knew about the planned punch-up.
Jack tells Helen that Barr "makes his own bullets". Someone with his knowledge of firearms would say that he reloads or that he makes his own cartridges, Barr reloaded cartridges; the bullet is just the part that exits the barrel.