Soooo if this is the second issue involving potential duping & specific ??? driven events/npc's - and Einherjar was the start, perhaps every single special interaction point should each be suspended & checked for similar abuses. I'd focus on everything end game current such as the other npc armor upgrade vendors in port jeuno & reisen myself. Maybe the Trial of Magians as well because of the delivery box. I'm not as knowledgeble as I'm still reorienting after a decade away.
But - its best to get them all done now voluntarily before we face the other inevitable result - pissed off banned people ruining it for everyone else left....