Superman could've saved the girl who ended up being beheaded by a lunatic. But he didn't.. And no, Superman wasn't somewhere else foiling a bank heist, being tortured with a lump of kryptonite by some nemesis of his, or helping his favored football team half a world away win a match. He was right there between the girl and the cleaver-wielding man. So what did he do? As the knife came down he moved aside to let the blade slice off her head.
His ways are mysterious; his plans for the planet inscrutable. All we can do is praise the all-good, all-loving, all-powerful invisible savior. Heil, mein Führer!