Can a Dealer Coach a Player During a Hand?

[BigBluffer]

2 players at the river. Board is J-J-4-4-K. Both players check. Player in seat 9 tables 3-3. Player in seat 6 moves his cards forward face down toward the dealer but nowhere near any other cards. Dealer says "Don't you want to turn your cards up." Player shakes his head no. Dealer says "Turn your cards up. You may have the winner." Player in seat 7 (out of the hand) says "Turn your cards up." Finally he turns over A-x, raking in the pot.

Was the dealer out of line here? I believe he was. I realize that cards read themselves, but if this noob doesn't know enough to turn over his winning hand, then he deserves what he gets. And I definitely think no dealer has any place telling a player how to play his hand.