What kind of a burglary is that? ***SPOILER***

First, it looked like Williamson's office door had no signs of break-in, it easily opened and closed. So he did not lock the door when he left the office. How can he keep the Leads safe with his sloppiness?

Second, the burglar gets in and take the Leads. Obviously he knew the value of those pieces of paper. A common thief will go for something more "marketable", like office equipment for example.

Third, the burglar opens all file drawers, steal some contracts and the phones. Why steal the contracts? Is there a black market for contracts?

Fourth, the "burglar" (we end up knowing who he was) knew that Williamson might come back later that night, so why waste time stealing the phones?