After Martin Luther King hears that his house has been bombed, he sticks his hand in the camera as if he is trying to prevent it from filming him. A few minutes later, at the house, a police officer does the same thing.
At 1:23 into the film, the Bayard Rustin character leaves his hotel and is walking down the street where he passes an establishment titled Posley Electric Appliances TV, Stereo, Radio. This takes place in December 1955, about 3 years before stereo sets were released to the public.