Player A Bets
Player B says "(inaudible)" and tables his hand (A-K).
Dealer mucks B's hand and pushes the pot to Player A.
Player A never shows his hand, but releases the cards to the dealer.
Player B then says "what are you doing, I said 'I call'?"
In your original example, you said player B had "the winning hand" but how do we know it if A-K wasn't the exclusive nuts on that board? Player A may have had the winning hand (or the same hand), but the hand never went to showdown to prove it. For all we know, Player A actually did have the nuts that hand. Player A, IMO, did not leave his hand unprotected, and Player B apparently waited until Player A's cards were mucked to bring up the problem. Unless this dealer was just ungodly fast and paid that little attention to his surroundings then it sounds like Player B may have been angle shooting here.