ok!
we are actually automatically delegating the radio to the PF while the PM is running the non-normal checklists (no differences if the PF is Cpt or FO).
This is a process that probably will change and probably the PM will be responsible for the radio both in normal and non-normal situations, while the PF is riding the horse!
We agree with the fact that it is alway Cpt final call to delegate the radio in every scenario, but ...