My take on this was Tony's luck returned with the death of Christopher, at least in his mind. He expected to lose, but just kept winning, and then it dawned on him that "He's dead. " The curse is lifted, and lifted by Tony being the murderous, cold-hearted bastard he truly is. He gets it. Be true to thyself, or, look out for yourself, fuck everybody else.
I think Tony might just whack everybody, Phil and AJ included.
I think the Salon writer was half asleep.
You're absolutely correct that Tony falling on the floor laughing was in celebration, as if the curse was lifted and luck was again on his side.