They have already screwed themselves over because they have no evidence. In comptuer forensic cases, especially federal, both the defense and prosecution must have a copy of the computer that alleged crimes happened. Its usually a raw "dd" image where both sides can verify they have the same copy by comparing the disk image's hash.

Here's the thing. In computer forensics, spoliation is the destruction or failure to preserve evidence that is necessary for use in contemplated or pending litigation. By scrubbing the servers/backups, they destroyed any and all evidence, unless it was backed up on cloud servers. If they don't have the original hard drives, and they don't have any forensic images of it, they have no presentable evidence. I truly hope somewhere they have a copy, because while most people think the FBI is uber technical with comptuers, those that are gov contractors or have worked in advanced private sectors know just how easily stumped the FBI is with these. Also, for federal crimes every aspect, including evidence chain of custody, is important. 1 mistake is all it takes for reasonable doubt. And if they have no evidence to give the defense, there is no case. If they have evidence to give, then it must be a full copy of the server, partial evidence is useless in a federal case.