I will jump in just very briefly.
Retroactivity is perfectly acceptable. We see it in the tax stuff all the time: The government puts out that it's going to change the tax code in this budget, and when the budget implementation act comes along, it's retroactive to the date of the announcement.
This isn't that kind of situation. Going back 30 years is problematic. It's not fair. It takes away.... I know there's a concern. All the lawyers will profit from a class action, but that's not what we should be concerned about.