When Silas is front of the judge in Tennessee, the judge is seen writing on a piece of paper in several consecutive shots. In nearly every shot, the pen in his hand changes.
After agreeing to hire him, Stan tells Silas: "Be at this address Monday at 8:00." When Silas picks up Mr. Wells, "December 30, 1952" is on the screen. December 30, 1952 was actually a Tuesday.
When the bartender is giving the free coffee to Hank's driver, there is a neon advertising sign that says "Leinies". Leinie's aka Leinenkugel's was a local beer that was not available outside of the state of Wisconsin at that time.