There isn't one.
Anything musk's dogs claim to find cannot be taken at face value because of this. Because there is no audit, and no evidence that they can offer that they didn't doctor their findings.
The next time they claim that a 170-year old person is receiving SS checks, they have no way to prove that they didn't subtract a century from that person's birthdate in some table.
Ah, this is something I haven't thought of before. This might not actually be spying, but instead just an attempt to plant fake results.