“Is this legal?”
I believe so. It is also NOT the job that the man was hired to do any more than it is my Pastors’ job to disprove scientific beliefs.
I think evolution is a correct theory of the development of life and I frequently take issue with posters who want to teach intelligent design in the classroom. By the same token, this teacher has no business attacking religious beliefs in his classroom. It isn’t even a philosophy class. He’s off base and should be reined in.