Yes I agree - I can voice from my experience. Even knowing an HR person and having that person's respect - they basically need to stand by the company - they may not agree, but they will do what is legally in the best interst of the company.
Likely these conversations will do nothing to help this poor woman, but it is also likely these conversations could have a huge negative impact to this bozo. So I'd suggest on your side - to keep it professional, but honest like you plan on doing. Try not to make it appear as if you can't stand the idiot (even if you do) - just give the facts without personal opinion.
The facts alone are going leave a bad mark on this idiot's record.