No was not suggesting a "cleared" descent I agree with you totally, if the pilot wants further descent - at their discretion it is.
Sorry if that didn't come across in my post, I see how I could have been misinterpreted. I was trying to highlight that legally they can be
allowed to descend below the RVC levels on a RIS.
Obviously as a controller you wouldn't want to be specifying heights to descend to in this situation, I had a maritime training aircraft yesterday under a RIS descending low level over the sea - reminded the pilot of his responsibility for terrain avoidance when he approached the RVC levels and continued to offer the service (no vectors) until he disappeared from radar i.e. like the situation you stated.
Take it easy
