But those couples/torques must be acting around a point to have created the rotation until equilibrium is reached.
Here is a secret. Physicists prefer to deal with steady state conditions because they are relatively easy to analyse. They ignore how the steady steady was arrived at. Sometimes you can fudge the transition from one steady state to another by assuming that all states in between are also steady states. In the case of a helicopter you might be going from resting on the ground to the hover. Following your own dictum, the pilot sees what the aircraft does and makes control movements to achieve what is required from moment to moment. The helicopter changes its attitude quite slowly and we can say that it never really rolls around any point as such. Nice, eh?