Had a similar experience with a remote sysadmin. Interviewing, he seemed to understand everything. He explained how he'd setup networks, details on using SSH for bastion hosts, etc. Seemed to really know stuff.

After hiring him, he was unable to even SSH to a box. As in he didn't know how to give us his private key, or how to configure his SSH client.

Maybe one guy takes interviews under other people's names then lets them mess up the work.