Use of internal tools. Sure, everyone has internal tools, but if you are doing customer stuff, you really ought to be using the same API surface as the public tooling, which at cloud scale is guaranteed to have been exercised and tested much more than some little dev group's scripts. Was that the case here?
Passive voice. This post should have a name attached to it. Like, Thomas Kurian. Palming it off to the anonymous "customer support team" still shows a lack of understanding of how trust is maintained with customers.
The recovery seems to have been due to exceptional good fortune or foresight on the part of the customer, not Google. It seems that the customer had images or data stored outside of GCP. How many of us cloud users could say that? How many of us cloud users have encouraged customers to move further and deeper along the IaaS > PaaS > SaaS curve, making them more vulnerable to total account loss like this? There's an uncomfortable lesson here.