Interesting that they only took one of the disks. a) a more aggressive forensic approach would avoid the server to be shut down if at all possible (getting data in RAM or on encrypted partitions) and b) it is very restrained in comparison to other seizures. I'd say that if they believed he were actively complicit or would do something to hinder the investigation, they would have been more aggressive, possibly went af…
"We have a confiscation order for the disks of your server, but we were allowed to leave one of them installed, due to the fact that you have a Raid1 setup."