Need a ruling on mucking cards

Was wondering if anyone knows the ruling in this situation.
Pot Limit Omaha
Board: Kh Jh 4c
Turn: 2c
River: 9c

A hand was bet to the river where one player showed a straight Q,10 and the other player showed top set and threw his other two cards towards the muck pile face down, another player at the table said the guy with top set also had a flush (which he did Kc 5c). This player grabs his other two cards and shows the flush. The dealer ruled this players hand dead. Said once the cards hit the muck pile the hand is dead, even though the half of the hand was face up (Kc Ks).

Is this the correct ruling for this situation?
Where can i find the rules for when an Omaha hand is considered dead?

[BluffTHIS!]

That was a correct ruling if any of the cards in the hand hit the muck pile. If the player had merely tossed them toward it and none of them had touched it before the 3rd player exposed some of the hand to show the flush, then the hand would still be live. Needless to say, even when cards speak, that 3rd player should not have become involved.

[liquid]

Per B&M forum conventions, this was a bad ruling. Correct ruling would be for uninvolved player to get a kick in the nuts.

[joewatch]

OK, theoretical situation:

First player shows str8, 2nd player shows hand, top set. Dealer declares first player the winner, 2nd player pushes his cards into the muck face-up. Then a 3rd player says wait - you actually made a flush, and you are the winner. Is the hand dead?

[BluffTHIS!]

[ QUOTE ]
pushes his cards into the muck face-up

[/ QUOTE ]

Touch the muck = dead. Period.

[liquid]

[ QUOTE ]
[ QUOTE ]
pushes his cards into the muck face-up

[/ QUOTE ]

Touch the muck = dead. Period.

[/ QUOTE ]

According to the floor guys in the B&M forum this is apparently not a hard-and-fast rule. Cards that touch the muck but are readily identifiable can be retrieved in odd circumstances. (A recent example involved a scumbag angle shooter who induced a "muck" by saying "You got it" -- but not "Fold" -- in response to a river bet.) No idea if the scenarios above qualify. I'm sticking with the kick in the nuts.

[BluffTHIS!]

An exception for angle shooting/cheating would not invalidate the fact that the rule is the normal criterion for determining if a hand is dead or not. I have seen myself in a B&M cardroom a situation where the floor having strong reason to believe 2 players were colluding ordered the dealer on the river to hold out the 3rd player's cards for inspection but after the dealer had symbolically touched them to the muck to make it a dead hand. I have seen a couple other occasions for similar reasons where a hand was ordered retrieved from the muck for inspection, although it was still dead.

Regarding those angleshooters, it is a player's responsibility not to fall for such shenanigans and to hold on to his hand until he himself has verified he has a loser. Anyone who accepts verbal statements from such people and mucks without seeing for sure deserves to lose the pot.

[ThePortuguee]

What about this situation:
Player shows all four cards and announces top set, verbally conceding defeat.

Dealer declares the straight the winner then collects cards from muck.

The uninvolved player pipes up about the flush.

In this case, since it's the dealer's job to properly identify the winner of every hand, can the cards be retrieved from the muck and the outcome of the hand changed?

once cards hit the muck, they are dead. and the uninvolved player should learn to keep his mouth shut.