Hmmm, seems a little bit like 'padding' ones logbook to me! Surely the aircraft commander/captain logs P1, and unless the other pilot is actually being tested, they're P2? I'm sure we'd all take a pretty dim view of such practices in the GA world.
Edited to add;- I've just discussed this with a very experienced aviator, and he said (and I quote) "if you were the aircraft commander you log P1, and if you logged the flight as P1 then you were the aircraft commander. ANYTHING else is nonsense, as the aircraft cannot have two commanders!"
Last edited by DaveUnwin; 2nd March 2016 at 16:14.
Reason: Added a bit!