I found the Dark Knight to be a fascinating film to watch, thinking through it "Christianly". Not least because of the scene with the giant black prisoner on the boat. (Score 1 for grace) Yet the guy who you sourced this from is spot on right. It is surely worrying when the Bad Guys in our movies have a better take on reality than the good guys.
"Never, never pin your whole faith on any human being: not if he is the best and wisest in the whole world. There are lots of nice things you can do with sand; but do not try building a house on it."CS Lewis, Mere Christianity, p163
Nice Lewis quote. Really great use of language.