It's a reincarnation story, so getting dragged into pain-in-the-ass situations is par for the course. Only that it's a bit different since we're not in the usual adventurer schtict.
Wasn't it just said that when its a dark fighter makes it that the fight is a 'dark fight' which had that whole zone thing occur which makes it impossible to escape? So why would this character who supposedly is in a agency meant to deal with them think that this dude was the who owned the dark card? Also why would she announce it if it was secret? Plus a quick glance of her surroundings would make it clear that its a shop and the ones she is accusing is clearly wearing aprons which would check out with them being in a shop and them being staff.