As I understand it, central to the argument in Kitzmiller was the claim that Of Pandas and People started out as a straightforwardly creationist textbook, and then was altered in response to Edwards v. Aguillard. But Edwards said that even though you can't teach creationism, you do some other things.
We do not imply that a legislature could never require that scientific critiques of prevailing scientific theories be taught. . . . Teaching a variety of scientific theories about the origins of humankind to schoolchildren might be validly done with the clear secular intent of enhancing the effectiveness of science instruction.
OK, so the court says "You can't teach out and out creationism, but you can do this," so someone alters a creationist text in order to do just this, and then Kitzmiller says that it's wrong to do "just this."
This I don't understand.