In the season 1 finale Shilo is arrested by some corrupt Louisiana cops on fake rape charges to tire him out before a game. When the team go to rescue him Thad (whilst recovering from a car crash only seconds before) proceeds to utterly demolish an entire room of the cops.
Marty calling out his son for being a jerk. He does accept the boy's homosexuality, but he disregards him because he is an ungrateful prick.
Harmon's method of regaining his kicking skills in "Rituals": tying Thad between the uprights and kicking the ball at him.