In the last scene at the dock in 1959, while Stroud is talking to the reporters, the Alcatraz launch is seen leaving the dock and heading back toward the island. When Stroud then talks with Tom Gaddis, the launch can be seen over Stroud's shoulder, back at the dock again, and is again in the process of casting off.
When Harvey is in Stroud's cell talking about the history book, it is with Harvey, but then is seen in Stroud's hands without him picking it up.
While Stroud is at Alcatraz, his cell is depicted with a window. All the cells at Alcatraz were located on inside walls with no openings to the outside.
In the opening scene, a tour guide tells visitors that Alcatraz inmates have included Al Capone, Baby Face Nelson, and "Machine Gun" George Kelly. In fact, Baby Face Nelson (aka Lester Gillis) was never incarcerated at Alcatraz. He was on the lam in August 1934 when the prison first opened, and was killed in a gunfight with FBI agents later that year.
After being put into D-Block at Alcatraz, Stroud's meal is served to him by his Fedo Gomez, who was his neighbour in the solitary block at Leavenworth. Gomez says that the warden has made him a trustee. Alcatraz never had trustees in its entire 29-years of operation. D-Block did have orderlies though (convicts in D-Block who were sufficiently non-violent that they were allowed out of their cells to sweep the floors and assist at meals) who would serve meals to other convicts in D-Block.
During the 1946 escape attempt from Alcatraz, inmates are shown obtaining a revolver and a lever-action rifle from a gun gallery. The firearms kept (and subsequently stolen from the gallery) were a Colt .45 automatic pistol and a 30.06 Springfield Bolt-Action Rifle.
In several cell scenes the sparrow shown on the window sill has almost no tail feathers, but an instant later the sparrow in Stroud's hand has long tail feathers. Also, the "sparrow" has a beak and shape more like a finch than sparrow. Pointed out by a retired National Park Service naturalist.
Mrs. Stroud goes to Washington sometime before 8 November 1918, to meet with Mrs. Wilson in lieu of the President, who, as Gaddis' narration states, was suffering from a grave illness. Mrs. Stroud says, "They've turned on your husband in his fight for peace." The references are to Woodrow Wilson's massive stroke and resultant infirmity, and his fight with the Senate regarding the Treaty of Versailles. All of that happened in 1919 and 1920.
When Tom Gaddis is waiting for Stroud at the boat landing in 1959, several automobile manufactures from one or two years later can be seen.
Stoud is shown being transported, working and eating alongside black inmates. US prisoners were officially racially segregated until 1968.
Early in the film, in an exterior shot when Elizabeth Stroud is in Washington DC to campaign for her son's death sentence to be commuted, California's mountains can be seen in the background.
At the start of the film, Gaddis states that Robert Stroud was put in solitary confinement in 1916, the year Kaiser Wilhelm II ordered the sinking of the Lusitania. This is incorrect on two counts. First, the sinking was in 1915, not 1916. Second, while Germany was then waging unrestricted submarine warfare and gave its captains carte blanche to regard any ships traveling to or from the British Isles as fair targets, neither the Kaiser nor the German government gave any specific order to target the Lusitania.