Back to the taking control thing.
A real world story of getting it right.
I was right hand seat, instructor, sat back arms folded but monitoring a very good student on his tailwheel (and an antique type) conversion. At 400ft just after take-off, we had a sudden loss of power. My student, not unreasonably said loudly and clearly "you have control Genghis".
I took control, called a Pan, and was manoeuvring to land back (eventually) on a disused crosswind runway. Partway through the manoeuvring - turning, stressed, trying to relate attitude to variably sloping hills around the airfield, and close to the ground, my student recalls noting that I was very close to the stall. His recollection is that he said something like "Genghis, check your airspeed".
I do not recall hearing that. I do recall at that point, glancing at the airspeed, realising from that and stick pressure and pitch attitude that I was close to the stall, and easing the nose forwards. Almost certainly I was responding to what he said, but too stressed to be consciously aware that that was what I was doing.
His clear verbal reminder to me almost certainly saved 2 lives and the aircraft.
I agree that a passenger should not be taking control from a qualified PiC under almost any circumstances. (Obvious circumstances when he might include PiC having a heart attack, or inviting pax to take control to have a go). However, it is excellent airmanship to clearly draw a safety concern to the attention of the pilot. The pilot then, who hopefully knows their aeroplane well enough to form sensible judgments, can do the right thing. In *some* aeroplanes that *might* be to continue to fly with the stall warner operating.
G