Interesting one, and I am interested in knowing who would and who would not retrieve the cards in this situation:
3 players remaining, NLHE, Flop is out, Heads Up, Raised Pot, 6000/12000/a2000, around 60,000 in middle, 375,000 in play. Player 1 Announces all-in and player 2 immediately announces call, at which player 1 shouts something along the lines of sh*t or f*ck and throws his cards over the table, with 1 landing face up and the other landing face down in the muck pile.
Now the muck pile is now 3 cards, I wouldn't want to go into the muck and retrieve those cards because of the etiquette violation, but they are both all-in, the card is easily retrievable and the player not in the hand knows what he folded.
My TD at the time ruled the hand live and retrieved the wayward card from the muck, and the player hand improved with running cards to make a straight by the river! I am not a fan of retrieving the card but I feel in this situation, that my TD did the correct thing, but would be interested to hear from others what their opinion is.
Best
Stu