The late game blow ups are definitely the most glaring and most memorable. Williams, no doubt, shares in the blame. That said, there is so much that goes on during the course of the game that it's hard, and unfair IMO, to attribute any loss or win to one player.
The Yankees are 16-7 in blowout games and 12-18 in one run games. That's the sign of a very good and somewhat unlucky team. It pains me to say it, but I have to give credit where credit is due.
That said, since June 13th, the Boston series, the Yankees have a -12 run differential. Maybe the Yankees are coming back down to earth. One can hope.