No, SC, not that Melfi is God. It's that the way her character has been developed over the years, I couldn't imagine her doing that to a patient, especially one that she had treated for as long as Tony. I don't think that it was in character, and that it was a cheap copout.
Obviously, Chase wants us to believe that she gave in to peer pressure, but I personally found the storyline completely unbelievable. First and foremost, I can't imagine a therapist blurting out a patient's secrets: A. In front of them and B. At a dinner party. The man would have lost his license!! Secondly, I think that it was out of character for Melfi to be so cruel to a long-time patient, especially one whose son was so recently institutionalized for depression and attempted suicide, who also had a history of depression.
Sorry, I didn't buy it. It seemed cheap and contrived, and thrown together at the last minute. Not only did the character and the actress deserve better, but so did the audience.