If you claim that something only moves in one direction, then one counterexample is enough to invalidate that claim. If you say in 99.999% of cases something only moves in one direction, then that claim can be invalidated by showing that either more or less of cases result as claimed... Isn't that straightforward thinking?

I seriously doubt that 99.999% of all toll roads are "ratchets" that only move in one direction, i.e. have never had the tolls lowered or removed, only increased. Examples of tolls being lowered and removed are also not extreme outliers it's one of the possible directions in which a toll's price can move and everyone and their aunt, but maybe not their dad, knows that.