Ok so two things here: you were probably never privy to the legal costs associated with Google being required to do a re-discovery. Google makes no promise to backup your data though there are provisions to restore things from the trash. Eg emails and files lost or deleted recently. Google then also have tools for you to do some of this work yourself eg: workspace.google.com/products/vault/ which meets your company legal requirement if you configure and pay for it. Again that’s not backup, that’s archive for legal discovery but lines can get blurry when multiple tools which solve different issues can effectively do the same thing.
Issue two: As an administrator there’s no denying even if they did you still wouldn’t have followed the backup 3-2-1 rule. You never had something on a medium not google even if you thought there were three copies and you consider Google replication to at least two physical sites.
To be honest I’m not experienced with Google but this is the normal expectation of cloud services. If you don’t have explicit terms of agreement to data recovery in a disaster, then you probably don’t have it.
Ps: I’m going to imagine your former boss paid a lot of additional fees, lawyer fees, google fees and court fees if it really had to be recovered that way. Nothing comes for free.
I’ve my own experience with Microsoft not having backups and directors not understanding that Microsoft explicitly do not promise backups. A user mailbox got delicensed, but when it was delicensed, the mailbox didn’t reattach. In the end it never came back after using our Gold partnership and paid support. We even had the guid. It was lost forever.
I reconstructed much of the mail, other mailboxes in the tenancy had emails from them or to them or were either cc or BCC so doing enough discovery I could eventually restore about 75% of the mail by getting the same email but from other mailboxes.
Nobody has ever doubted using a backup solution is required since.