This is where a good disciplined approach to operating the systems should be built by the airline check and training department. Pushing a methodical approach to something as simple as setting flap, eg, you can place your hand on the flap lever when called for, visually check you have the correct lever, check the speed is below the limit for that setting, move the lever incrementally to the desired setting (this reduces the chance of flap asymmetry). Immediately check the flap indicator is moving in the correct direction, and in unison, keep your hand on the lever until the desired setting is indicated as called for.
My take on what possibly happened is in a training environment the trainer will be watching the flight path and alignment with the runway. He has skipped some final crosschecks whilst fixated on the runway and approach path the flying pilot is following. As a result grabbed the wrong lever, never visually checked, never confirmed settings. The lack of power from both engines suddenly would startle any pilot, especially for no apparent reason. Sully saw the geese coming, so the recognition of loss of power was fairly quick and then they kicked into a response to it. The PF especially would not really expect both engines to suddenly not produce any torque, but still indicating running status, I can understand why she would have been very confused, and they just didn't have excess time to go through a methodical check of why, with the ground approaching fast.