Minimum shutter speed setting controls the interaction between Auto ISO and the shutter speed in P and A exposure modes.
But here, when I started this thread, I was in movie M and I control both the aperture and shutter. fuzzynormal stated the shutter speed must be faster than the frame rate, but I could set frame rate to 60p and shutter speed to 1/30, which doesn't make any sense. There must have been a legitimate purpose in some specialized situation, I would imagine, and this is not a bug. However normal usage must prevent that from happening. I felt that the camera must be able to do something to prevent me from making such a user error, which I believe is easy to make - just one inadvertent touch of the shutter dial, and there goes my footage. So far setting it to ANGLE/ISO does what I want.