Yeah I put insurance in quotes for a reason.....
Sorry your subtlety was lost on me...
As it happens I'm on agreement with you as far as the pilot logging PIC and the instructor logging nothing- that is quite straight forward and I can't see what the CAA has against that.
Just looking back through my logbook I seem to have several 'Satisfactory LPC' comments complete with signature and instructor's licence number and has been logged (instructor filling in my logbook) as P1(s). Not actually sure what that means.