What are you doing asking for this advice on HN. If you think it could actually be a legal issue contact a lawyer. They can tell you if you have liability and help you write the email.
Chances are, I’m not the first person this has happened to. I’m looking for prior experiences that may help before jumping into a potentially expensive attorney consultation.
If you don't want to contact a lawyer directly, you can probably find some sort of a help line that deals with legal issues in regards to employee relations. They should at least be able to give you a good idea as to what your next steps should be.
