True - without being able to see outside the airplane (because of darkness, clouds, fog etc.) it's easy to get disoriented. That's why airplanes have instruments (the attitude indicator, a.k.a. artificial horizon) that pilots are taught to rely on rather than trusting their own "gut feeling" about what the plane might be doing. Guess this copilot needs some additional training...

If only planes had some kind of measuring devices that could tell their angle from the horizon and their speed through the air

While flying manually is important to keep skills sharp, trying to fly this under VFR would not be a good idea

When you fly at night, even in VFR mode, you trust the instruments over what you think you see.