I would say that it's the fact that it's about "teaching the controversy" and it's aimed at middle/high school. It's bound to confuse.
"Ok kids, we're discussing evolution. I am obligated to tell you that it is controversial. Not within the scientific community, mind you, but with a number of religious people. But, as per the law, I have to inform you that you will see controversy over evolution"
"Science is interesting, and if you don't agree you can fuck off." -Dawkins