Factual error: In golf scene, Kevin Spacey is supposed to be playing golf in St. Andrews. The intensity of sun and the surrounding fauna suggests they are actually playing on a course in the mid latitudes of the US. (00:11:30)
Continuity mistake: During his second interview with Jack, Stone tilts his body to the right in the front shots, but remains straight in the back shots.
Factual error: When the Senator is looking at the rent ledger, there are entries for each property as well as the date that money was collected. One of the dates is 2/29/74, yet 1974 was not a leap year. The only leap years in that decade were 1972 and 1976. (00:56:30)
Deliberate mistake: The (fake) confession letter was postmarked from Ohio and sent to Allison Connor, 331 Henry Lane in Hilliard, MB 21243. No U.S. state has a postal abbreviation of "MB." The way the "B" was written in thick bold letters made it resemble a "D" - "MD" represents Maryland (where the film apparently takes place). Also, there is no current 21243 zip code in the U.S. There is a 21241 for Baltimore City and the next consecutive zip code is 21244 in Baltimore County. The created address LOOKS real. (00:50:44)
Factual error: Close to the end of the film Michael Reed is traveling from Philadelphia to New York City by train early in the morning. The sun shines on his face from left side which is impossible in the morning, as the left side of his face faces west during that direction of travel (from south to north).
Continuity mistake: Jason spits blood onto Joker's chin which changes spot wise and shape wise by the next shot.