Continuity mistake: When Kate and Reggie discuss in her motel room, Reggie is sitting at the table intent on eating an apple. In the first shot he's going to put the apple in front of his mouth, but in the next shot he doesn't accomplish any action. (00:55:51)
Continuity mistake: Just a minute before the shootout at the border in Juárez, a shot from above shows a cop approaching the Cartel members in the red car from behind. However, when the camera cuts to a different angle, the cop has vanished.
Answer: They haven't crossed the border yet, and the gang members were there to kill them. They had no intention of actually crossing the border.