When Jonah is shooting at the Charger from the back of the RV, he fires nine rounds out of the gun. The gun he is holding is a revolver, which commonly contains only six rounds. Some revolvers can hold up to 10 rounds, but the one used in the movie looks as if it can only hold between 6-8 rounds.
In Fat Lou's Roadside Diner where Milton first sees Piper, the other waitress takes his order and he orders coffee "black, with sugar". There is already a coffee cup on the table and a sugar dispenser is already there. Then, as Piper quits her job and walks out, there is a shot of a lone coffee cup on the table and the sugar dispenser is gone. If Norma Jean had actually cleaned the table, the cup would be gone and the sugar dispenser would still be there.
When the '57 Chevy appears at the end of the film, it has unlit amber marker lights in the grille. After Milton and The Accountant get in and drive off, the marker lights are lit, but showing clear/white light
After the shoot-out is over when Milton is having sex with the waitress from the bar, he is between her legs which are wide open. In the very next cut as he stands up, the legs of the waitress are tightly closed together.
Near the end of the motor-home chase, the trunk lid of the Charger is damaged and flapping open as the car goes over bumps, but when they stop beside the road, the trunk lid is closed and shows no visible damage.
When the news about the manhunt for King is on the TV set in the bar (in Oklahoma), the station ID on screen begins with a "W". Most new radio and TV call-signs west of the Mississippi begin with a "K", however there are stations on the air that do not follow this rule, notably KDKA in Pittsburgh, Pennsylvania, KYW in Philadelphia, WFAA in Dallas, Texas, WBAP in Fort Worth, Texas, and WACO-FM in Waco, Texas.
When the hydrogen truck being driven by the Accountant explodes the primary fire ball created is blue green. If the tank had been filled with hydrogen the fire ball would have been primarily yellow in color when it ignited.
When The Accountant is driving the hydrogen truck, the truck is incorrectly labeled with a UN hazardous materials placard bearing the number 1075. 1075 is the UN number for liquid propane, not hydrogen.
After Piper drives off from the diner and the Charger begins smoking, the needle on the speedometer drops to zero when the engine quits and she coasts to the side of the road. The speedometer is not controlled by the engine and would have still shown the speed. The tachometer would have dropped to zero when the engine quit running.
The news refers to the Colorado State Police, but in Colorado it is the State Patrol. Also the State Patrol wears light brown pants, not like the troopers in the movie. Also CSP would not investigate car theft, as their primary responsibility is traffic safety.