In this case, you point to the hypocrisy of being uncontactable but demanding your contact details, except that Google does provide support to customers, and in this relationship they are essentially a customer of your CT log, and given the criticality of that service they rightly expect the service provider to be held to a high standard. I don't think they're holding you to a standard that they themselves wouldn't agree to be held to for a service that critical. I've got to make it clear that this is my personal opinion though.