During a game of Hearts in the motel room, the number of cards in Longbaugh's hand changes. As the camera goes around showing the characters, he somehow loses several cards, which reappear in the next shot.
During the gun fire in Mexico, Obecks' right leg switches position between shots. First his right leg is under his left leg then it's next to left one and after he gets shot by Longbaugh we see his right leg under the left leg again.
Jeffers (Taye Diggs), while shooting at the extremely well lit parking lot, which would disallow all the fire to be seen from the handguns, shoots more than a few shots with no fire seen from his handgun. Once behind car while shooting at Mexican cop and a few times when shooting from beside the car he'd put Robin (Juliette Lewis) into. Bad editing continuity.
At the end of the film, after the shoot out at the motel, Parker and Longbaugh wonder why the doctor, followed by Abner, went south. When we see the two cars that are supposedly headed "south," we can see the sun rising behind the cars, to the drivers' right, which would mean that they are heading north, as the sun rises in the east.
When Longabaugh shoots the first Federale with the sniper rifle, the sonic crack of the bullet is heard, and the impact is seen, before the report of the rifle is audible, indicating a range of over 700 yards, far beyond the range of Jeffers' pistol. Yet Jeffers is able to put down effectively accurate suppressive fire at that range.