At what point does Google’s incompetence imply organizations that use its services are liable for negligence? What if this were a bogus subpoena for a lawyer’s

At what point does Google’s incompetence imply organizations that use its services are liable for negligence? What if this were a bogus subpoena for a lawyer’s privileged conversations with a client? A doctor’s communications about reproductive health with a patient? A political consultant working for the democrats?