I'm confused. Am I supposed to punish my son or not

My kids go to a year round private school. They have about 3 weeks of summer break and just went back. Literally the second week of school I'm being called in the principals office. My son(16) got in trouble because he wrote a book and it's been going around the school and people have been reading it and one of the teachers got their hands on it and said it was disgusting, obscene, and vulgar. The teacher that found it was one of the special Ed teachers and his English teacher was also in there. The weird thing was both teachers weren't on the shame page. The special Ed teacher said it was disgusting and my son had no business writing it and allowing other students to read it, while his English teacher who read it when it was brought to her attention said while it's definitely graphic and could be considered obscene, it was well written with a really good plot and the students are old enough to decide what they want to read. The Spanish teacher showed us a part in my sons notebook were he went in detail... A rape. The main character got raped and he REALLY described what was going on.... She showed me more parts and I cab understand what she means by its obscene. There were other sex parts in the book although she mainly pointed out the homosexual sex parts and seemed more angry about those... idk. By his English teacher was saying the kids are 14 to 18. Not 4 to 8, they've seen worse and we shouldn't be trying to stunt my sons creativity because they think it's too vulgar. At this point these 2 teachers are screaming at each other and the principal dismissed us because he couldn't get the under control.... My son asked was in trouble and me and my husband said we would discuss it over the weekend. We read the book and definitely graphic, definitely vulgar. Kind of concerning but giving his age maybe not. Idk. It was definitely well written and not a bad book. Just.... a lot.... And since nobody ever came to conclusion in the principal office idk what we are supposed to do.

I'm not that concerned about the rape part I the book. He read the lovely bones last month which has rape in the book. And we watch Handmaids tale. My point is I don't think he got the idea from the book from being sexually assaulted or sexually assaulting someone.