Superman reverses time just enough to get to Lois before the road splits in half. What? He doesn't stop the nuke? He doesn't prevent Hoover Dam from bursting? I suppose we can assume he did these things, but not only are they not shown, they're not even hinted at. And Jimmy was on the road where Supes had left him, which was AFTER the dam burst. So the disaster happened, and Superman didn't do anything to change anything, but, somehow, the road doesn't split open this time because...??
Also, I get the idea that Earth's rotation didn't literally reverse, except for this one fact: Superman flies around the Earth, it (seemingly) reverses, then he FLIES AROUND IT AGAIN IN THE OTHER DIRECTION until it's rotating properly again. If Earth wasn't literally reversing direction, why would he need to do this?
Also, I get the idea that Earth's rotation didn't literally reverse, except for this one fact: Superman flies around the Earth, it (seemingly) reverses, then he FLIES AROUND IT AGAIN IN THE OTHER DIRECTION until it's rotating properly again. If Earth wasn't literally reversing direction, why would he need to do this?