So, if for example Nate answered:
“No respond to that, that means, I take 8, and lose the game.”
fills in the match result slip, both players signed..

and THEN he realize that Omenspeaker should have died because it is 0/0..

That means there's no concession, and his loss was preceded by an illegal action (taking 8 damage from a dead 0/0). But both players has signed the result slip.

If that's the situation, do we rewind?
(Assuming none of them have clean up the cards, everything is still on the table)

What if they have scooped up their cards, and Nate realize this on his way to report the result slip?

I would say that if they signed the slip, and definitely if they scooped their cards (as they cannot recreate the gamestate) then - it REALLY sucks for the guy who conceded, but its over.

Originally posted by Maykel .:

If that's the situation, do we rewind?
(Assuming none of them have clean up the cards, everything is still on the table)

What if they have scooped up their cards, and Nate realize this on his way to report the result slip?

Personally, I feel that in the first situation, you are going to have to use your best judgment. You could argue, and quite strongly, that once the slip is signed by the player, the match is over. See MTR 2.4. That's a pretty clear statement that what's done is done, and backing up to the point of error is moot. Alternatively, you could try to return to the point of error and let the match continue. I don't feel that is strongly supported in policy, but I could understand a judge ruling that way.

Obviously, in a situation where the cards have been scooped up, the player has conceded. Mistake or not, there's no way to restore the game state and it's pretty clear Nate acted in such a way that he lost.

Hmm..
I see..

Okay then, thanks. :)