Goofs

In the first goodbye scene when Sam hugs Will, her hands keep changing place: first, her left hand is behind his neck, then suddenly the right one is, then again the left.

When Will takes the gas cans from the train wreck, chances are they would have been diesel fuel as army vehicles are usually diesel-powered.

After the collapsed lung repair, Will and Tom are still going west. Then a setting sun is seen reflected in a door mirror, as though it was setting in the east. But then the sky in front of them is painted by the setting sun.

Will and Sam outrun a pyroclastic cloud, which would be impossible since its speed averages 700 kph/400 mph.

Will finds an abandoned fire truck and uses the SCBA face piece like a filtering face piece that industrial workers use. They don't work that way.

Cadillac did make a V8 version of the CT6. The one in the movie is a v6 version as confirmed by the 3.6 badge on the trunk. The sound of the engine is wrong all along the movie.

When stopped by the police at the Ashland Heights barrier, Will looks out the car window and it seems like he's wearing some sort of plasters on his forehead, cheek and nose. But these are actually reflections on the windscreen as can be seen when the camera moves.

While Will is driving and Tom is injured in the back seat they hold a conversation via the rear-view mirror. The shots of Tom reflected in the mirror though have been flipped and show him as if he was seated on the other side of the car. You can tell the shots have been flipped as the reflected image looks like Tom has a band around his right wrist, while for the rest of the movie it is actually on his left.

When the main characters are tailing a car in the dark with their lights off, there are several shots where the headlights of another vehicle are clearly visible behind them. This is presumably the camera crew, as there is no one following them.

After Will has driven through the ash cloud, the part of the windshield where the wipers cleared the ash is perfectly clean. There would be some smearing.

Near the beginning, the morning after Will has dinner with the Sutherlands, he is in bed sleeping when a low-flying plane flies over, making a lot of noise, yet he is able to hear the mobile phone that's barely making a buzzing sound.

After finding Sam, Will sleeps. After he wakes, he walks out of the house and sees a large fire in the distance. Will walks over to find Sam and her neighbor at a significantly smaller fire.

During the escape on the covered bridge, Will shoots through open windows to his left and his right. After the first bike rider falls, the driver's door window is closed. After the second biker falls, the passenger door window is closed.

At the 1hr 20sec mark the sound of the engine coming from the Cadillac is suddenly a V8 when in fact they are driving a 3.6L V6 as seen on the boot badge.

When driving from Coeur d'Alene, ID, to Seattle, WA, the road signs continually show I-5 North to Seattle. I-5 runs from north-south between Canada and the border with Mexico, passing through Seattle. Will is traveling east-west across northern Washington state. He would be traveling on I-90 West between Coeur d'Alene and Seattle (passing through Spokane, WA) if he stayed on the freeway.

When Will is on video chat with Sam and things start happening where Sam is, he asks her "What's going on?", then when he starts to say "Can you hear me?", he pushes the End Call button.

When crossing the covered bridge (1:17:00), Will turns the car around twice using techniques only someone trained in defensive driving would know how to perform. There is nothing in the film to indicate that he had any related skills, specifically his unfamiliarity with firearms.

Nobody in their right mind would accelerate at such speed when visibility is so low (storm scene, before stopping under a bridge).