But ultimately it doesn't matter if the RJ forget to advise ground control that they weren't clear, or couldn't because of frequency congestation. You(we) are ultimately responsible for the safety of your(our) aircraft. No one else is.
Don't see anywhere in my posts on this or other threads on this subject where I have disagreed.
We don't 'scoff' at it. It's SOP in the U.S. also.
Shame it didn't happen this time then. There have been quite a few posters who have dismissed the idea of the RJ telling ground he wasn't clear, which surprises and disappoints me.