board plays on river, player flashes to dealer then mucks

[ericicecream]

limit game local casino, river board is 98765 no flush, a player bets and two players call. the better shows QJ and dealer announces "plays the board" second player is a guy who appears very tired and not in tune with the game and is going through his stack quickly, he flashes his cards to dealer (I think it was A7 but didn't see it clearly) and then throws his cards face down toward the muck, dealer mucks the cards, third player shows 65 and dealer says "plays the board" and splits the pot 2 ways. The tired guy is oblivious to what just happened and is waiting for his next two cards.

Is the dealer correct here?

After the split, should the dealer advise the player to expose his hand next time?

Do you, as a player, advise this player to expose his hand next time?