"Taxpayers were advised that there is a "work around" because the sale of business property was a "one time deal" OR that there is an option for requesting a recalculation by IRS."

This Advisor is confusing IRMAA and ACA. Which means that person should not be listened to for anything, because that is a basic understanding you should have before giving anyone advice. And whoever helped them submit for the Credit obviously did not guide them for ACA "life changing events" follow up.