The $4 is the abuse fee.
Cartwright! Cartwright!
In fine Harvard -Gruber style this pompous jerk has apologized for being an ass, but only after being publicly shamed online. There is probably a requirement that one has to be an arrogant prick to find employment at Harvard, a discredited institution.
Is he Crimson-faced with shame?
Know it all Harvard prof; next he'll run for office...