As other posters have said, his petition will be rejected. It’s time to move on. A 3 isn’t a bad score, it’s actually very good. And even if by some miracle they do accept the petition, I highly doubt that the experience of your daughter’s single teacher will outweigh the opinions of multiple experienced CB-trained teachers who actually graded the essay. There are amazing universities that do take 3s, and the universities that don’t, probably won’t waive freshman English requirements anyway.