Education is a big special case: teachers should be legally obliged to provide as accurate and fair a presentation of established truth as possible.

You realize that, depending on how one interprets this, evolution might have never originally been brought into classrooms at at all? It wasn't until it started getting taught at at least the university level that it started to spread beyond a fairly small group of naturalists...

A. to make claims about what is true and what is not [is free speech]
B. to slander someone [isn't]

A does not include B?