Other mistake: Towards the end of the movie, when Superman drops Gus off at the coal mine, Gus begins talking with the coal miners about him and Superman. He then rips open his shirt (as if he had a Superman costume on underneath). How did Gus know that Clark Kent tore his shirt like that in order to change into Superman, or keeps his suit under his clothes at all? The only people who know this fact are the ones who have seen the transformation from Clark to Superman, i.e. the audience.
Other mistake: When Vader first arrives at the station, he and the Commander are walking past rows of troops. If you look carefully, you will see a Stormtrooper in the back row with his helmet tipped so far forward it's almost off.
Other mistake: Steve Martin, a surgeon, never once wears a surgical mask while performing any operation.
Other mistake: When the Soviet attack occurs, farmer Jim Dahlberg carries his blinded son to the farm's shelter. The dust cloud from the nuclear blast in this shot is blowing from right to left, yet the flag in front of the house is blowing into the opposite direction. (00:59:50)