The cleanliness of the bite depends on what kind of shark is doing the biting. A Tiger will tear at the wound while a great white is much cleaner (apparently). Also it's only a possibility of teeth being left in the wound.
I checked Rupert Murdoch's movements for the day and he was not in the office. He used to be Australian and tends to take a clean bite from competitors, so my money's on either him or that offensive, rentaquote female tory mp whose name escapes me.