You don't get to judge anybody. Once criminal charges result, it's not you versus him anymore, it is the State of Indiana versus you. There may also be an action from the State of Indiana versus the other guy.

At the national level, the retrograde registration requirements have not been found unconstitutional. There has been some state action (and I have no idea if Indiana is one of them and I'm not inclined to look it up for you). However you do have a point on the wording of the statute. However, I suspect you will need the assistance of a lawyer for the exact way to ask for relief from registration.