Billie is seen cleaning swastikas off the porch columns. The amount cleaned/smudged changes between shots.
When a guard lets Geiger out of the cell, the position of the guards' hands on the bars changes between shots.
As Mr. Cobb enters the judge's office he removes his hat. In the next shot he removes his hat again.
When the Lieutenant tells Walter Matthau that his son was killed, the Lieutenant is wearing an Army Commendation Medal on his uniform. The ARCOM or Army Commendation Medal was established by the War Department on December 18, 1945, well after WWII was over.
After calling Major Lilly on Sunday morning, Harmon Cobb inquires about the name of Corporal Ernst Schmidt. After a brief exchange, Major Lilly replies that "Private" Schmidt died of natural causes.