Need help with a rulling

[russian ace]

$25 SNG. 3 players left. 2 get paid. Button folds. SB raises. BB calls. The dealer puts the flop out. The he does not realize that they have chips left so he burns and turns. What should be done? The guy that ran the game decided to just nullify the hand. This seems wrong to me.
Thanks for any help.

Ace