I'm more than curious if that is what the document really says.
unless it was a QACA in which case you could actually generate forfeitures, I would have thought the incorrect match is tossed into suspense and used to reduce future safe harbor (it was after all 100% vested when made inadvertently to the plan.) I'd argue it is a correction under EPCRS, you are putting the plan in a position it should have been if the error hadn't occurred.