This is a hard one. However, my gut tells me that film schools aren’t going to take too seriously the opinion of a high school film teacher. Especially if her work is really good. It’s not clear that this character should be writing her LOR anyway, especially if he has a vindictive streak. I’d focus on the academic recs and perhaps an outside art instructor if available.
Also, your daughter needs to think through how she will handle film school, where her work will be critiqued - many times very harshly - pretty much every day. It will be a major exercise in humility. So this might be great practice for that. Just a thought.