Despite what I wrote in #2, I think we have firmly established that the testing officer is in fact PIC. I know I am when I do a flight test, even if I keep my trap shut and touch nothing (which invariably means you passed and acted "in command" and without supervision) .
How you log it afterwards ... I would say dual but I have never looked to see what "you" write. I don't even care. I am over the moon if "you" pass and somewhat depressed if "you" fail.