If you throw a rock over the fence, the hit dog is the one that hollers

Meaning: if criticize someone and they react strongly, your criticism hit home with them and it is proven to be accurate

I told awl them boys that they just won't as country as me and never could be. Most of 'em just glared at me, but boy, ole Hank sure gitted fired up when he heard that. If you throw a rock over the fence, the hit dog is the one that hollers.