Character mistake: During the scene in the diner, there is a sign that reads "EMPLOYEE'S ONLY." There shouldn't be an apostrophe.
Character mistake: When Mac describes what he saw after Blaine was killed, he states that he "capped off 200 rounds with the minigun." At the rate the minigun fires, and the length of time Mac was shooting, he fired at least 10 times that amount. Perhaps he meant to say "capped off 2000 rounds." This adds to another mistake: the ammo pack Blaine carried only holds 500 rounds but much more than that is fired during the course of the film.
Suggested correction: He actually says "capped off 20 rounds, in the minigun...full pack" just the word spacing is a bit odd. 20 rounds refers to his normal gun which ran out of ammo quickly.
No, he says "capped off 200 rounds." I've just watched it with subtitles on. What I heard (200) matched with the subs.
Character mistake: The Daily Planet newspaper headline "New publisher for your favourite paper" has "favourite" is spelled the British English way. Since Metropolis is in the United States it should be spelled "favorite."