Charging for ROVs are simply a fee charged for additional work requested by the client that is added from the original SOW. If the appraiser finds that they made a mistake, then obviously that should have been included in the original report, thus no fee would be warranted. This is nowhere near the intent of the management section of the ethics rule.
However, as a side note, it is very pertinent the lender's choice to pressure the appraiser for value...a violation I highly doubt they want to face. just sayin...