I love Jenna Ortega, she's an amazing actress and so I have watched a bunch of stuff she's in... Miller's girl is one of them. Back when I first watched it, I did a review on Twitter that no longer exists... basically I said it was good but so weird and did not need a like 2 minute scene of the teacher jerking it to his students story.
I was reminded of this movie from a Cairo edit on TikTok and my brain did what it does and honed in on the random tiny spark (this is the same thing that happened with the Jinu is Rumi's dad post)... that tiny spark was the fact that Cairo didn't technically falsely accuse Johnathan Miller at the end due to the fact he was having an inappropriate relationship with a student.
How far Cairo and Miller went is up for interpretation. Some believe all the physical stuff (kiss and sex) was fake while some believe he did actually do those things with her. I'm in the middle where I think the kiss was the furthest they went physically and the sex was a fantasy she had based on the hints she was getting.
Cairo and Johnathan did kiss in the rain when he was returning her phone, that crossed the physical boundary between anyone in a teacher/student dynamic, no less a 50 year old with an 18 year old. But before that, its still crossing any line between student and teacher, going out to an event together, sharing cigarettes, Cairo receiving special treatment (getting a jump start on her midterm)... all of this is grounds to report him for an inappropriate relationship.
Obviously, she handed in the story she wrote of them having sex as part of the report so there was that false portion and definitely played it up so it was worse sounding but the kiss, the poetry date, the sharing cigarettes, getting special treatment... all of that is grounds for punishment.
Cairo is in no way the hero of the movie, she was not a good person at all but she is a victim. A man in power took interest in her because she knew his work and used her for the ego boost because he liked how she made him feel. Winnie is also a victim here because Filmore was leading her on, he mentions they never crossed physical boundaries like miller did but he was also flirting and acting too buddy buddy with his student.
Poor Winnie is the real loser in this situation, she enjoyed the attention from a teacher which was then lost when Cairo reported Miller (thank God) and she lost her best friend/crush in the process because she was so shitty. Justice for Winnie Black.
Honestly, Miller deserved losing his job because if all he needed to cross boundaries was for someone to read his book, if it wasn't Cairo it would have been someone else and might have been worse.
TLDR: Cairo reporting Miller wasn't entirely fake, very exaggerated but not fake and Miller deserved it. Winnie deserved better.