Anyone ever heard of a situation where an unqualified check pilot takes another pilot for a check ride and when the out of check pilot crashes the plane then claims that because 3 take off and landings had been done the out of check pilot was P1?
As far as the "carry passenger" rule is concerned, the out of time pilot signs off the plane, and IS P1. He illegally carries a current, qualified, passenger, (who is aware of the situation,) just in case he finds things getting of his comfort zone. Also a valuable second opinion when he starts to worry about a noise/smell/vibration he's forgotten about, in a 50+ year old wood and fabric aircraft.