Towards the end of the movie, Early violently smacks his gun across Brian's temple, above his left eye. His temple is shown in a subsequent shot as very bloody, yet there is no visible injury (or bandage) in that spot a short time later as Brian is shown driving down the road chasing after Early & Carrie.
In the scenes where Early and Brian are at the bar and Carrie and Adele are in the hotel room, when Adele is painting Carrie's nails you can see the sun shining outside. When it goes back to Early and Brian, it's clearly night time.
When Early is digging the hole at night and talking to Adele, you can see the top of his pants. When he climbs out of the hole, he is obviously naked.
The foursome begins the journey in Atlanta (The Georgia Dome is visible during the Breakfast Cereal Conspiracy conversation). After they've traveled 480 miles, Atlanta landmarks are still visible outside the car (Equitable building, Spaghetti Junction, etc)
The amount of vodka in Carrie's glass changes inconsistently between shots while she's sitting on the couch, watching her slides, trying to convince Brian to go to California.
When Brian and Carrie visit the murder scene, Carrie's Nikon clearly has a motor drive, and we hear the sound of it advancing the film, but we also see her manually advancing the film.
We first see Early's pistol laying in a bag on the car's back seat. A closeup clearly shows it to be a parkerized U.S. military World War II M1911A1 (with commercial grip panels). But later, when Early and Brian are firing it at an abandoned building, Early says it's a Japanese pistol.
Early Grace drinks a beer during his parole officers visit, parolees are prohibited from imbibing or using narcotics in Georgia and most US states without modification of their parole terms by the court or their parole officer.
When the scenes go from the 2 men drinking in the bar and the women in the motel it's daytime in the motel and night while they are out drinking and daytime when Duchovny when he gets in and is arguing with his wife.
The scene where the guys are out shooting pool, and Carrie and Adele talk in the motel room about Early having been in jail, is supposed to be a nighttime scene, but the window next to Carrie, and the bed they're sitting on, is blown out with bright sunlight.