I agree. I'm a long time HR professional; I used to be the one who did the investigations and I've taught classes in how to identify illegal harassment and what to do about it. But how you should respond to your HR at this point needs to be determined by someone who has details you should not put out on the internet; in other words, your own lawyer. You have what sounds to me to be a pretty good case (unlike about 95% of the people who post here) and I would hate to ruin it for you by giving you advice that turns out to be bad because I didn't have all the facts.