When the two boys begin arguing in Leper's dining room, how does Leper negatively characterize Gene? What does Gene then do that seems to prove Leper's charge against him?

The boys argue because Leper seems so different, Gene has no idea how to relate to him and becomes verbally hostile. Leper characterizes Gene as a savage and accuses him of causing Finny's accident. Gene then physically knocks Leper out of his chair..... this seems to prove the description of "savage."