He would have gotten away with it if he didn't say "Proverbs 29:18". Though this is a reference from the Bible, he's not preaching religion. He could have used a line from Buddha, Confucius, Plato, and a host of other people (Religious in there own right).
Could he have used this quote? "As a Christian I have no duty to allow myself to be cheated, but I have the duty to be a fighter for truth and justice." Would he then be labeled a Nazi? (I quoted Adolf Hitler).
Could I get away with Quoting the Bible? Honestly, I was a Christian until I moved to Oklahoma but greatly distanced myself when I moved down here.
Well, I do quote the bible without religious intent! It doesn't mean I am jamming some religion down someones throat, I do it because everyone is familiar with the book.