Surely silvestrov miswrote and meant "converse", not "inverse".
And it's because the classic statement of the Dunning-Kruger effect is that the unskilled have an unrealistically high estimation of their own abilities. It doesn't talk about what the skilled think.
Actually, it does say. People assume that they're closer to average than they are, whether they're above or below the true average. The Wikipedia link above even says "the highly skilled underrate their own abilities, suffering from illusory inferiority."
And it's because the classic statement of the Dunning-Kruger effect is that the unskilled have an unrealistically high estimation of their own abilities. It doesn't talk about what the skilled think.