The UK CAA were quite unequivocal about this issue; I was hour building for the purposes of granting the privilege of CPL(A). My putting time in the P1 slot and the safety pilot's name in the operator column invalidated my claim to P1 status. No argument. The FBO said was legal and correct in Spain; UK CAA said inappropriate and inadmissable in the UK.
You
could put down that you were the operator but you would be found out in a subsequent inquiry - check the receipts that you have kept (?). You would be defrauding the system. The chances are that Juan Doe has put his name down as P1 as well.
You have no comeback with the FBO. I had to fly these hours and it cost me a further £1900 when I could least afford it.
So, if your instructor/safety/language proficient pilot takes off
You are not the 'sole manipulator of controls' in the flight, therefore you are not P1 for the purposes you may be flying. I implore the OP to contact the UK CAA to find out what is the correct procedure in these circumstances.