The consultant that come in to rescue them in between this guy going, and me being able to come and start full-time:
- Didn't know what virtualisation was
- Didn't know what WDS / SCCM was
- Didn't use GPO at all (everything was copy-pasted batch file in NETLOGON)
- Didn't know you could failover things like DHCP.
- Didn't know what DFS was.
- Didn't know what spanning-tree was. (He thought that turning on spanning-tree and having multiple routes was going to bring the network down).
- Had never heard of LACP, let alone used it.
- Was unable to replicate all the above (because obviously he knew he could sell it to other clients) at his other main customer's sites - in some cases for up to 6-9 months each, even WITH my documentation.
- Oh, had no documentation except for a password list.
- Had licensed thousands of copies of iPad apps illicitly which - with iOS 8 - all fell over and stopped working.
So, no, it's not that surprising at all. Even the guy-brought-in-to-clean-up-after-the-previous-guy had the same kinds of problems but at least understood that backups were necessary.