Revision of ESA decision and ‘Offical Error’

I am aware that a successful appeal against a benefit decision can be classed as an official error when the arrears due result in an overpayment of housing benefit.  I was wondering if anybody knows whether a revision of a decision by the DWP would also satisfy the same criteria?  In this case an appeal was scheduled but subsequently lapsed following a revision by the DWP - so there is no tribunal decision implying that the DWP made a mistake. However, I believe the original decision was an error and that the client did not contribute towards this. Any thoughts/help would be much appreciated..