Re: Vanguard messup?
(On a more serious note) I just remembered I had a broker screw up a Roth conversion once.
My instructions were clear as day to do partial conversion, listing the shares to convert on their form with proper boxes checked, but they did a full conversion.
They admitted the form was filled out perfectly correctly, and corrected the transactions quickly. But later, I got the tax form from broker showing the full conversion amount. IIRC, they had said when they made the earlier corrections, would be no problem with tax reporting.
I kept calling (and, I think, writing) but it took many tries to get them to really fix it instead of just promising that it was fixed, or would be in a few days. They also told me on the phone that the correct info was given to the IRS.
Later, I got an audit-type/revised taxes (or whatever they call it) letter from the IRS, because the info given to IRS from the broker showed the full conversion. I already had a corrected/revised form from the broker, and submitted it to IRS.
So, I do suggest you get the errors corrected quickly. I don't know how you can check that Vanguard really gets the correct info to the IRS.