If the business was not profitable enough to afford Excel, OpenOffice is an almost Excel feature parity FOSS alternative. Had that file been stored on a cloud drive and regularly backed up to local or alternative 3rd party backup solutions, this issue not only wouldn't have happened but it also would not have been able to happen.
Hindsight is 20/20. though. Don't store important documents on a cloud server that you have no backend access to without having a contract in place regarding the responsibilities of maintaining your data.
It is your responsibility as a business to understand what your legal, statutory and regulatory requirements are and then put those requirements into your service agreement or contract. Or ensure those requirements are configured as part of the deployment of the service.
Either way, it's not Google's responsibility to know what your requirements are. They can assume and develop features that support particular regulatory requirements. But it is the responsibility of the organisation doing business with Google to stipulate their requirements.