Surely the solution is for the 'check out' pilot to be P1 and the pilot being checked to log nothing, that way there is no ambiguity at all about who is in command.
Yes but if there is simply 2 PPLs then the person being checked can log the flight but they can only record the sole manipulation of the controls and not P1 time.
If the P1 is an instructor then they can log the time as dual.
Ambiguity over who is the real captain can cause accidents.
and insurance / legal disputes.
Regards,
DFC