kathy, glad to see you still with us :)
yes, it's always a slippery slope, but sometimes a line has to be drawn. in this case, if she is homeschooled by her mother, and she and her mother have this unified "religious" belief that the father can't love his daugher if he doesn't share their religious beliefs, well, even giving all kinds of slack for all kinds of religious beliefs, this isn't a healthy situation for the daugher.
although i hate to draw hard conclusions from limited evidence, i'd wager that this particular "religious belief" is merely a manipulation by the mother wrt her daughter and ex husband. my guess is the court saw this, and decided that a broader environment was in the girl's best interest.