You just proved yourself wrong

You did lose data... The connection to some
known Libraries
Kovid is not saying you CAN'T use a NAS.
He is say that ANY networked drive makes the Calibre, transnational way of Library management, unreliable under ALL conditions.
IMHO The performance hit to allow a tiny fraction of Calibre users to USE Calibre with a NAS is not warranted.
NAS are great for backups of your library.