This whole incident, including the leak, has Bill and Hillary writen all over it.
Sure does.
BINGO! I don't think Bergler would think of using that telephone excuse himself. Most likely Bill told him something like, "Hey, just say you have to make some sensitive phone calls. They'll trust you since you were head of the NSC. And you won't really be stealing documents since they were ours to begin with. Just borrow them and conveniently lose a few. And don't sweat it. They'll never find out."
The problem was that Bergler isn't nearly as slick as Clinton. He probably had guilty sweat pouring off his body which aroused suspicions. Bill could have done it without breaking a sweat but not Sandy.