Improper distribution of Excess Contributions

Background:

Our office was engaged to review prior administration for a 3 year period (2016, 2017 & 2018).  After proper determination of highly compensated employees, it has been found excess contributions were overstated by a significant amount to one highly compensated employee for 2 of the 3 years.  (overstated by $13k 2017 and $10k 2018)

I have not found any specific guidance on the correction for the improper distribution of excess contributions.  Has anyone had this type of correction?

I don't have the foggiest idea.  Other Qs come to mind - why would this be studied at all, other than to prove that someone screwed up and it's time to move on?  I don't think that genie can be put back in the bottle.

Are you sure?  I would think this is an overpayment. 

Since the basic tenet of EPCRS is "put the plan back in the position it would have been in, absent the error", I'd argue you could return the excess distributions and revise the 1099s.  Would have to "think about" how to address earnings lost (or realized outside the plan).