Rules Question

[Zybomb]

Three players are left in the hand on the turn. Player 1 bets Player 2 calls... Player 3 still has a hand but has placed it in a stupid way so its hard to see. The dealer deals the river. Player 1 checks, the next player thinks, then the dealer sees that Player 3 still has cards so he holds action....

Now I know if the 3rd player calls, the river is shuffled back in and the deck is reshuffled.... but what happens when the 3rd player decides to fold.... does the original river card that we've seen (the natural river) remain.... or is it still shuffled back in?

I was in an unfortunate situation today in a $600 pot with an opponent obviously drawing and he was given 2 rivers in which to hit (the 2nd river he hit!) despite the fact that the 3rd opponent still folded. I called a floor ruling and it was said that if the river card had been seen it must be shuffled back in regardless.... i didnt think this was correct but a few other ppl sitting said it was that way.... Is this correct?