> But that doesn't mean they go wrong all the time

They do, in fact, go wrong all the time, or at least, all the times that the actors involved are sufficiently confident that they think they can both gain something and get away with it.

Which is why the price of freedom is eternal vigilance, both to limit the occurrence of the conditions in which they go wrong, and to identify and correct the points where that prevention fails before they become a positive feedback loop.