The One White Witness

The tag at the end of film states that during the reparation hearing several black survivors testified along with one witness. Given the 70 year gap, that witness was most certainly a child at the time of the incident. Is is intended then that we are to understand that the young white boy Emmett (who is forced by his father to accompany the mob and ultimately renounces his dad & runs away) is that sole white witness?

"Sacred cows make the best hamburger."