[WindyLakeReturn]

>The ball starting to move without anything acting on it would violate other principles of classical mechanics.

Isn't gravity acting on the ball? Ideally a ball balanced a the tip of a bowl has 0 net force, but only because it has the force of gravity pulling it into the bowl and an equal force from the bowl pushing back. This would require assuming a reality where there is no smallest particle, no atoms making up the bowl or ball as they are both perfect mathematical objects comprised of infinite points no matter what resolution you look at them at.

The issue is that such a system, if it can be created by rolling the ball up the bowl with perfect precision from any direction, indicates that it is unstable and may reverse at any point, but without any obvious reason causing it to do so. So either the system has some non-deterministic factor which allows for the perfect stability to break at an arbitrary time in an arbitrary direction or it isn't time reversible as the ability to roll the ball up the bowl cannot be reversed.

Looking at it another way, can you tell the difference between a ball I perfectly rolled to the top of the bowl 10 years ago and one I did 10 seconds ago?

I do wonder if we've added so many assumptions, with mathematically perfect objects and infinite precision forces that we have created some sort of paradox. We have hit levels of perfectly spherical cows that cause even the perfectly spherical cows to complain about unrealistic standards.