I was playing 1/2 in a card room last week when an interesting situation came up which had me stumped.
*8 handed game, 3 way action on the turn;
*first and second position check, button bets $50.
*First position goes all in for $71 total and second position calls.
*The action is back to the button to either fold or call $21, but the dealer overlooks this and puts out the river.
*Floor comes over and instructs the dealer to take back the river and tells the button the action is on her.
*floor tells the dealer to shuffle the river back into the deck;
*the dealer starts doing this when he realizes he also picked up the muck and combined it with the rest of the deck.