jbrbbt

Revealing mistake: Look carefully at the train when Superman is using himself to hold up the track during the earthquake. It's obvious the wheels of the train are not even touching the track as they pass over him.

jbrbbt

Plot hole: When Superman goes after the missile that's heading for New Jersey he leaves Metropolis (which is actually New York City). He would have met the missile head on, but he appears to catch up to the missile from behind and while it's still over territory somewhere around the Grand Canyon, so he probably could have stopped both missiles before the second one hit the fault line.

jbrbbt