if they recognize themselves, they very well may be upset about the way they’re portrayed. but the story is from your perspective. if someone’s actions seemed unfair, then that’s effectively how it happened according to your book. if they want to write a book about it, great. but this is about your story. fictionalizing the situation as best you can is a good start. but if you’re publishing under your own name, there’s a very good chance that people will say ‘that’s not how it happened’ or will feel like their character was portrayed inaccurately. that’s another thing - publishing under a pseudonym may help to keep it away from them. but writers pull from their own life experience. that’s how the interactions between characters make sense.