Dealer mucks hand, what's the correct ruling?

[The Riz]

Playing at Majestic Star in Gary, IN last night. Guy raises to $50 preflop. I pushed all in. He called, and everyone heard him call, except for the dealer, who somehow thought he said fold, and grabbed his cards and pushed them into the muck. Two of the players kept their eyes on the cards and knew which two they were in the muck pile.

The floor was called. What should their ruling have been?