Healthcorp is still liable, you can subcontract a job, but uou can't subcontract the responsibillity.
What I mean is that Healthcorp should have procedures to test the backup, and as soon as it failed, they should inform the government.
It can also be asked, why Healthcorp only had one backup of the data, when it is best practice to have a 3-2-1 backup system, if Archivetopia offered a service as a 3-2-1 solution, why didn't Healthcorp select that? If they did why didn't they verify the claims of the service?
At the end, Healthcorp would get hit with a fine, but they in turn could sue Archivetopia for breach of contract.