I learned about "who has control" early on during the CFS course on the Gazelle on a "mutual" sortie. Myself and my stick buddy got a little out of synch and suddenly both thought the other had control and was "having fun". When we got to about 100 degrees nose up, and rapidly increasing, we both looked across at the other and then thought "????" because we both realised the aircraft was flying itself - we both had our hands on our knees.
Then we both said "I have control!" at the same time, grabbed the controls together, and mutually wobbled our way through a "roll off the top" of what was somewhere between a mega-wingover and a half loop. Thankfully we both tried to roll the same way or it could have got even worse!
We had a good mutual debrief about that one i.e. we both used similar swear words...
