When the Marshal starts to walk on the dam you can hear the wind whistling meaning there is at least wind of Beaufort 5 or 6 , but he finds the drawing on the dam while it actually should have been blown away. Also when he picks up the drawing there is no wind anymore.
It is unexplained why the Marshal stops om the dam. How does he know that, because only the direction was mentioned.
Frank cocks the pistol twice before the assassination attempt.
It was first amazing that the charcoal drawing survived unprotected so far, but when the marshal picked it up, it should have been pretty brutalized by the elements and very smudged.
The sidewalks in Canon City have modern curb cuts for wheelchairs.
The small German postwar Messerschmidt "bubble cars" that are shown on the street were built in the 1950s because the Messerschmidt aircraft company was no longer allowed to build aircraft after the war, so they started making small bubble cars. If Germany had won the war the company would never have had a reason to produce a car. Other bubble car manufacturers would not have built such vehicles either if Germany had won the war and had not therefore economically ruined.