I also work in HR...and I know that part of my job is often knowing about difficult decisions or conversations before they take place. My role is to provide advice on compliance/policy/procedure/etc to the person acting on behalf of the company and often participate, not to pave the way for the conversation or event with the employee. Obviously, you are in a very difficult spot as this is your AH. IMHO, you have a duty, as a HR professional, to keep this confidential.
Also, from a codie perspective, I think you need to step back and allow your AH to feel the consequences of his actions. I know this is difficult enough when it is not your spouse, so I can only imagine how hard this is.
I wish you strength as these issues are addressed around you, and encourage you to stay out of the way.
