I'll only agree with the aspect that it "makes sense" in that films world and absolutely no where else. Let's be real even today's comic book films wouldn't try something so outlandish. The truth is i'm not even what that did? If he caused the earth to go back in time then where did that stuff that happened in the past go? The missile and everything? The whole ending did rub we the wrong way in that film, which for its time i think was pretty good overall.