why does the doctor have to apologize?
I was annoyed that a medical doctor had to apologize for being skeptical of herbal treatments. If it was clear to the viewer that Cassie put incantations or spells or some kind of witchcraft on the herbal concoctions, then it would be believable in the context of the movie that people were being cured by these potions, but they seem to be just plain herbs, and, to a doctor, there is little or no scientific evidence that they work as well as medicines. He was right to be upset if she seemed to be persuading people to avoid medical treatment.
The movie seems to be saying that these herbs work as well as traditional medicine. I, myself, have tried some of them until I found that they really don't work if you're seriously ill. I know there are still always believers--but Cassie is supposed to be magical and that should be the point, not just a statement about the superiority of natural remedies, because that opinion would be on shaky ground.