So this happened at FNM last week (Regular REL, Standard format) …
Aardvark is borrowing my sweet Blood Baron deck and is playing against Nairobi (names changed to protect the innocent) playing against Nairobi, who is piloting some permutation of Junk Reanimator. Aardvark thought that
Blood Baron of Vizkopa got bigger and flying-er if you're at 30+ life *or* if your opponent is at 10- life (not *and*). So he aims a bunch of burn at Nairobi's face to get him to 10, or maybe a little less, and swings with the Blood Baron, ostensibly for the kill. Nairobi starts scooping up his cards while Aardvark tells me about his sweet play. Then we all realize .. oh wait, that says “or”. Uh ….
Since they both seemed pretty relaxed and not particularly fussy about the situation, I tried to reconstruct the game state as best I could, which both players seemed happy with. Nairobi had scooped up his graveyard and hand and started combining them with his library, but his permanents were still on the battlefield. I asked Nairobi if he knew for sure if any specific cards were in his graveyard, and how many cards he had in his hand. He picked out a few, and Aardvark agreed. He said he had “3 or 4” cards in hand. So I said, fish out those few cards you said were in your graveyard, put them there, shuffle up your library, draw 3 cards, and continue playing . They seemed happy about that fix. It was more of a “lol oops” thing.
How would the rest of y'all have handled this? What if this was at Competitive? (I'd say Nairobi conceded, and give Aardvark a Warning for PCV.)