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 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 rounds.
At the end scene when Piper regains consciousness, her white shirt is all splattered. A moment later her shirt is spotless again.
First time that Milton enters Piper's car he gets in to the passenger seat with the window up. When they show the interior shot of the car, the passenger window is down.
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 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.
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.
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.
The reflection of the Moon in a window of the car is not a mirror-image as it should be.
Milton's facial wound changes inconsistently between scenes.
In the opening chase scene after the pickup truck strikes Milton's Riviera and flips over, a roll cage is clearly visible inside the truck's cab.
At the end of the opening scene, when Milton shoots the driver of the pickup truck in the chest, the prop tire iron he's holding clearly breaks in two when it hits the ground.
At about 12 minutes 30 seconds, when Piper (Amber Heard) says "Quit my job. Again!" her lips continue to move, no sound.
During the chase through the industrial building, yellow "Caution" tape can be seen along the strung along aisleways where the cars run, apparently to mark the chase route.
At the bar in "Oklahoma" the waitress asks for a membership card because it is a "dry" county. There are no "dry" counties in OK, that's Texas.
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.
At the hotel near the Bull by the Balls nightclub there are palm trees. Palm trees do not survive in Oklahoma's climate.