Find an attorney. Don’t give us any updates. Consider deleting this. This posting could be considered legally discoverable. Not hard to figure out who you are from your submission history. Best of luck.
Why would it matter if this was discovered?
Because he said something at all. Though, HN is probably not akw hanging fruit for anything. Unless your founder is here and knows you are. Or if you re-use that username then when they look for your social media they will find it.