Well, no, I'm not describing Linked Timestamping (hereafter LT), because LT is a system for creating trustable timestamps, and I'm talking about a system for auditing the state and operation of a service. Hash/block chains are common and going to get more common. LT, Git, Certificate Transparency, Bitcoin, and now what I'm describing.

And, further, I'm not suggesting you trust a third party, but if you feel I am, please point specifically at where.