I know what you mean Mike, but I'm going to give him some specifics.
Assuming women's or JO play: 6-3-J,K J. Pushing off with the pivot foot from a place other than the pitcher's plate is illegal. K. (Women's and all JO play) Pushing off and dragging the pivot foot in contact with the ground is required. If a hole has been created, the pivot foot may drag no higher than the level plane of the ground.
It often gives people the impression a pitcher actually starts, leaps forward and pushes off a second time. While that is indeed an IP, it isn't the only manner of crow hopping.
Sometimes it isn't a "re"plant at all, which is why it isn't really relative to the rule.