I don't think the Plan is allowed to be put in a better position than if the mistake was not made.
In this particular case it sounds like the size of the correction was calculated in error causing an "over correction", presumably by the brokerage house, the excess of which should be returned to the brokerage house.
But honestly I'm not 100% sure on that, it's just an educated guess.
Sounds like the exact same reason. This was a public service question for all those bundled providers whose ignorance will cause potentially irreparable harm.
If I could them as a client, rest assured I will take care of it for them. I would just hate to win the business only after this monster rears its ugly head...