Google having it is the same thing as external auditors having it. They've said as much on several occasions (e.g. "If you don't have anything to hide...").
Wrong. Google has a vested interest in protecting the information (whether or not they internally exploit it for contextual advertising is another issue). External auditors have more incentive to leak the information to increase public outrage at Google.
Google's vested interests are irrelevant. The government can take any or all of their information any time they want to.