The quote was "According to one specialist, the Web site contains about 500 million lines of software code."
So I would highly doubt that "software code" would also include comments.
I don't usually count comments to as lines of code. I didn't realize that some people did. Perhaps I'm just unusual in how I count them. It seems there's some ambiguity however so it's very possible that they were counting comments after all.
Still, I agree the figure is outrageous.