The Headmaster, you defeated yourself with your own argument. Velocity is about groundspeed, not airspeed. Inertia does indeed need to be considered and is a problem at low altitude because it is exacerbated by the unrelated but relevant issue of perception as well as the lack of recovery space if it goes wrong. Third factor: inexperience.
At normal turn rates and altitudes it is simply not noticed but combine the other factors and it is a definite threat.