pat - the new york guys knew he was seeing a shrink, but that doesn't mean they know where. in season one when tony was in his depressed fog chris unknowingly tailed him to the building that tony sneaks through to go to his shrink.
It's certainly a very plausible theory that he was tailed because after the phil hit his guard would be down and not necessarily trying to shake a tail, and it would mamke more sense for the timeline (because if pat had set him up, you would think the killers would have been waiting for tony at holsten's instead of coming in behind aj well after tony had arrived)

little man - i agree, except i think the soprano ship was sinking. tony's inner circle was decimated in the war, he has rico indictments coming down, his professional life was in shambles and I believe albie was going to double cross tony because he thought tony was to much a loose cannon and had broken so many rules I just can't imagine another boss would want to cast his lot with him unless he absolutely needed commission support, tony wasn't on the commission and albie had backing of a second new york family and therefore didn't need tony for anything
Therefore I think Patsy would not have seen enough benefit to stay with tony