Another scenario. Many years ago I had only a Bronze certificate on gliders. I flew with a gliding instructor/PPL in his Jodel. This was the first time I had ever sat in a light powered aircraft. The pilot had only one eye.
Returning to the airfield he got a piece of grit in his good eye, turned to me and said "to hell, you do it" half way down the downwind I closed the throttle and landed the aircraft in the manner to which I was accustomed. No problems.
Who logs what?
He is medically unable to fly. I am unqualified.