Bernard's recordings on a regular basis (and knew about the convo with Elsie).

Also because he arranged for all the data to remain only stored onsite, it'd be logical to assume someone would try to workaround that at some point.

re: the Dolores sessions, a theory I read on Reddit was that they are in the past, and that Bernard is actually a replica of Arnold, and so in the flashbacks that's actually Arnold interacting with her.