Nearly a decade ago, when I started to learn to fly, I had a series of incidents with my then-instructor where his hands-on teaching style conflicted with my taking mental ownership/responsibility for the flight, leading to mistakes. Nothing unsafe, but still a hindrance to training. I wrote about it earlier.
A few years ago, the dual situation occurred, this time with me as a passenger.
A local pilot offered a ride in his fine-looking steed. From what I heard, he had considerable experience as a former commercial (airline?) pilot, but now retired and flew with his family. His plane and ours must have been maintained at the same shop at the same time for us to make contact. Mutual curiosity led from one thing to another, and before long, there we were at the runway threshold, ready to fly.
I was sitting in the front-right seat, where an instructor/co-pilot would - but for small aircraft, that role is not required, so passengers may sit there too and enjoy the scenery. I certainly did not ask for any piloting powers/responsibilities for the trip, since I was just curious about the plane.
He throttled up to get moving. The airplane was just coming out of maintenance, which is ironically a riskier time to fly than hours later, so we were all paying plenty of attention to noises, instruments, the feel. Sure enough, a few seconds into the takeoff roll, I felt an odd vibration, and the engine monitor indicated one of the twelve cylinders being more than a little off. I asked the pilot whether this was normal - it could be. As we were still accelerating, he said "no".
What happened next was a shock. He asked me what we should do.
It was ridiculous. We both knew I was not familiar with the aircraft type, let alone his particular one. We both knew who was in charge as legal pilot-in-command (he), as I quickly reminded him that it is his decision.
Still, while we were still accelerating, nearly at lift-off speed now, he hesitated and asked me again what to do. This time I simply told him something like "I would stop.". This, he understood, pulled back the throttles, and we safely aborted the takeoff. (Chances are very good that if we had gone flying, nothing bad would have happened; at worst a partial engine failure that this plane would have been able to handle.)
In this case, the pilot abdicated his responsibility, maybe due to lack of confidence in single-pilot operations. In my original "two cooks" case, I (a student at the time) abdicated my partial responsibility, due to conflicting signals from my instructor. Both situations sucked. On the other hand, maybe something similar happened with the Asiana Flight 214 in San Francisco. Maybe all the three (!) qualified pilots in the cockpit were deferring to each other for resolution of their problem (too low & slow), and this time there was hell to pay.