There’s nothing you should or can do. Isabelle is just giving you a slap on the wrist. If there was proof or evidence that you discriminated against a guest based on their race, your account would’ve already been suspended or removed.
Was your review actually removed or did this come in retaliation to your review? Did your review contain anything about race?
In your thread two weeks ago, I suggested standing up and fighting back against this guest. I received quite a bit of criticism for that but I still think that was/is the best course of action. The bully won’t stop until confronted.
If I’m putting two and two together here, it sounds like your guest has completely ‘taken the gloves off’ and is trying to sabotage your character by being a smartypants and throwing whatever will stick at you.
If he really did make this up just to get back at you, printing out that email and mailing it to the HR department or Ethics office at his place of employment along with an explanation of how it started would be extremely embarrassing. He would have to explain why he claimed to be Latino and refused to pay for his family breaking things and vomiting in a house he rented. Like I said before, when he stayed at your home he represented his company because he actually told you he represents his company. He brought that into the picture so you’re not hitting below the belt.