If the cards were easily retrievable, as suggested, it probably means they weren't in the muck. If so then I agree with rexarse and co, that common sense means they are retrieved and hand played out
I was at the table when this happened, the cards were absolutely in the muck. The guy who was all in was sat in seat 9 and placed them clearly on top of the pile of cards that constitutes "the muck". They were only easily retrievable because he put them on top, not inside.
But you could identify them easily, as could he?
Yes, I could be absolutely certain of which two cards he had held.
Could the Dealer?
If so I'd say his hand is retrieved and placed face up and the board dealt out. Whether he gets to eat his pudding depends then on the cards not some f==k up
I can't be sure if the dealer saw where the cards were placed, but they were directly on top of the muck and I'd say chances are that she did.