As I was recently reminded here, under Japanese rules, dead stones are only removed from territory. So a dead stone in dame - due to some kind of seki position - would not be removed. But to me it seems like that’s just an indication that they didn’t quite finish the game.
I’m wondering if there’s some kind of weird situation in which there might be a dead stone that should remain in the dame region of a seki, or if the situation indicated above is always an indicator of an unfinished game.