A 4 hour RPO is generally considered pretty tight in non-transactional environments and the recovery is comfortably in so it would seem their protections worked.
If you corrupt the data files and the archive logs you're losing data. It's just a case of when you last put some files in a place that didn't get FUBAR'd. Moving them every few hours is normal and 4 hours is a common figure used as it's a good balance.
I'm sure that Salesforce will be crafting more expensive and complex solutions for more stringent objectives as we speak.
Wouldn't want to be a CIO explaining that they lost that amount of data if the business did not "allow" that amount of data loss though.
Biting the hand that feeds IT
