Corrected entry: In the scene between Gene Hackman and the sheriff in the barber shop, they are talking about baseball, Hackman says that he always liked baseball because "it was the only time a black man can wave a stick at a white man and not start a riot." The movie is set in 1946, but the first black player (Jackie Robinson) didn't start until 1947.
Corrected entry: When Gene Hackman is shaving Brad Dourif he cuts him on the right side of his face. Once Dourif is out of the chair, the cut is on the left side of his face.
Correction: He was cut on the left side of his face. It only appeared it was on the right side because they were showing this from the viewpoint of the reflection in the mirror.
Corrected entry: Gene Hackman and Willem Defoe visits the house of Deputy Pell twice. After the first visit Gene tells Willem about the wedding photo (where some of the invitees show the Ku Klux Klan sign with their fingers). However, Gene has not seen the photo at this time. He does not see the photo until the second time he comes back to talk to Mrs. Pell.
Correction: It's fair to assume that he saw the photo during the first visit in its proper place in the living room - just because we're not shown him looking at it doesn't mean he didn't see it. This would make more sense of the second scene too - that he would bend down and pick up this particular item, of all of those scattered round the room, because he'd seen it before and it had some significance for him.
Correction: The film is set in 1964, not 1946.