At one point Woody Harrelson tells Ernie Hudson that there are no real cowboys from Texas. However, later when asked about Bill Pickett, Woody didn't know who he was and replied ,"Oh, William!". Willie M. "Bill" Pickett is from Texas and was called the "Greatest Cowboy" of his day.
When the cowboys are on the road, Pepper says that he is past Tulsa, Oklahoma. They are later seen going through a desert landscape. There are no deserts past Oklahoma
When the conductor stops the subway, John Stark and his hostage Teresa are thrown forward towards the camera from the abrupt halt. But the front of the train is to their left, not in front of them.
When they are driving away in the pickup truck after escaping the shooters down the fire escape, a bullet 'stars' the windshield (no bullet hole). A few moments later, the bullet hole appears.
Sonny: [Pepper drags Sonny behind a Horse Carriage hiding from the Owners of the Waldorf Astoria]
Pepper, those People are guessing that You skipped the Bill.