Floor call in LV

I was the floor on duty during a 10-handed, $2/5 NL Hold'em game when this happened. The players are on the turn, 3-way action. There is about $70 in the pot and the first guy bets out $50 to which the second guy mucks. The dealer believes there to be only two players in the pot and therefore picks up the muck, deck, and board and jams them together to prepare for the next hand and ready to push the pot Uh Oh, a 3rd player has cards still. Now normally, and as was my first suggestion, I asked if they just wanted to chop the pot? The original bettor says no because he has the best hand. All the table can agree on about the board is there was one Ace and two diamonds, they disagree on the other card ranks and suits. Think about what you would do here, then read on to the next complication....


.... so now the guy claiming the best hand turns up his cards (A-10 diamonds) saying "see, I have the best hand". The other player also turns up his cards A-10 off and says he'll call. What's your answer now and how does it differ from before the cards were exposed?