So this law firm, with business-critical emails, were ONLY storing them in an outlook PST on a local machine?
God, they deserve everything they get, not a recovery.
I mean, if they had Exchange - LITERALLY no excuse. Just delete the mail account on the client and re-load and it'd pull back down from the database.
But LOCAL Outlook folders? Obviously with "delete from server" turned on rather than just syncing to a huge IMAP folder held in the cloud somewhere? And then stored on only ONE client, but they just-so-happen to expect the tech to back everything up for them?
Law-firms have serious and quite clear obligations on the retention of emails. These guys failed from the start, even if the tech-guys managed to restore something.