Get your heads out of all these details. It's smokes and mirrors.
The question is basically not if the skipper was out of his seat trying to pull any kind of HAL lifeline, it's not if the copilot could not fly a bus in degraded mode, it's not about where CB's are, or FAC/ELAC PRIM/SEC switches and how and when, by what OEB they might or might not save your day ....
The question is why do such questions about laws are still unclear after all these years and why do we have so many recipes as to how to deal with such upsets in a bus when ....
... such switchings and questions almost never arise with other FBW systems.
If you can answer that question, and even better remedy the unclear bus situation to the level of these other systems, then we are finally entering the correct path by eliminating at least one huge hole in a Swiss Cheese slice.