Correct Ruling?

[Fianchetto]

Mid limit B&M Full game.

I open raise from MP, folded to the BB who calls. We're heads up. Dealer scoops the bets into the middle of the table and prepares to deal the flop when the CO says "Hey, I said I got 3-cards! It's a misdeal", he didn't have them anymore, he had mucked them apparently.

Then the button chimes in, "Yeah, I only got dealt one card, I never got a second card." He also has no cards at this point.

Presumably the CO got dealt the button's second card, I don't think they are lying about this. However neither of them has any cards now.

As I was raising, I did hear CO mumbling something to dealer, but at no point did the dealer stop or say anything until the CO spoke up again after all preflop betting was completed. Dealer is now trying to tell him if he had 3-cards its just a dead hand anyway, he says "no", and wants a decision from the floor.

Eight other players have acted on their hand, two players want a misdeal declared but neither of them has a hand, and it appeared to me that they had mucked in turn.

What do you think is the correct ruling in this situation?

Results to follow. Thanks.

Additional information: I opened with a marginal hand (K9s), but I'm almost certain it is better than the BB's hand who is a very loose player.